Table 3. Regulators of PD-L1.

Type	Regulators of PD-L1	Tissue type
Inflammatory signaling	IFN-γ	↑ multiple tumor types (Dong et al., 2002), endothelial cells (Mazanet and Hughes, 2002), glioma (Wintterle et al., 2003), renal tubular epithelial cells (Schoop et al., 2004), colon cancer (Nakazawa et al., 2004), monocytes (Brown et al., 2003), dendritic cells and macrophages (Brown et al., 2003; Kryczek et al., 2008), neutrophils (de Kleijn et al., 2013)
	IFN-α and IFN-α	↑ endothelial cells (Eppihimer et al., 2002), monocytes and dendritic cells (Schreiner et al., 2004), melanoma (Garcia-Diaz et al., 2017)
	TLR4	↑ macrophages (Loke and Allison, 2003), bladder cancer (Qian et al., 2008), monocytes (Huang et al., 2013), dendritic cells (Mezzadra et al., 2017)
	TLR3	↑ dendritic cells (Pulko et al., 2009), endothelial cells (Cole et al., 2011), neuroblastoma (Boes and Meyer-Wentrup, 2015)
	IL-17	↑ monocytes (Zhao et al., 2011), prostate and colon cancer (Wang et al., 2017b)
	IL-10	↑ dendritic cells (Curiel et al., 2003), monocytes (Zhao et al., 2011)
	TNF-α	↑ endothelial cells (Mazanet and Hughes, 2002), myelodysplastic syndrome blasts (Kondo et al., 2010), dendritic cells (Karakhanova et al., 2010), monocytes (Zhao et al., 2011), monocytes (Ou et al., 2012), RCC (Quandt et al., 2014), breast cancer (Lim et al., 2016), prostate and colon cancer (Wang et al., 2017b)
	IL-4	↑ RCC (Quandt et al., 2014)
	IL-1β	↑ dendritic cells (Karakhanova et al., 2010)
	IL-6	↑ dendritic cells (Karakhanova et al., 2010; Kil et al., 2017)
	IL-27	↑ dendritic cells (Karakhanova et al., 2011; Matta et al., 2012), ovarian cancer (Carbotti et al., 2015)
	TGF-β	↑ dendritic cells (Ni et al., 2012; Song et al., 2014), T cells (Baas et al., 2016) ↓ renal tubular epithelial cells (Starke et al., 2007), monocytes (Ou et al., 2012)
	IL-12	↑ endothelial cells (Eppihimer et al., 2002), monocyte-derived macrophages (Xiong et al., 2014) ↓ THP-1-derived macrophages (Xiong et al., 2014)
Oncogenic signaling	MYC	↑ melanoma, NSCLC, HCC, osteosarcoma, leukemia and (mouse) lymphoma (Casey et al., 2016; Atsaves et al., 2017; Wang et al., 2017a)
	HIF1α	↑ breast cancer, prostate cancer (Barsoum et al., 2014), mouse myeloid cells (Noman et al., 2014), NSCLC (Guo et al., 2017)
	HIF2α	↑ RCC (Messai et al., 2016)
	STAT3	↑ lymphoma (Marzec et al., 2008; Atsaves et al., 2017), melanoma (Jiang et al., 2013), HNSCC (Bu et al., 2017)
	RELA	↑ primary monocytes (Huang et al., 2013), melanoma (Gowrishankar et al., 2015), NSCLC (Bouillez et al., 2017), breast cancer (Xue et al., 2017)
	MUC1-C	↑ NSCLC (Bouillez et al., 2017)
	JUN	↑ lymphoma (Green et al., 2012), melanoma (Jiang et al., 2013)
	CDK5	↑ medulloblastoma (Dorand et al., 2016)
	(PTEN loss) PI3K-AKT-mTOR	↑ glioma (Parsa et al., 2007), dendritic cells (Karakhanova et al., 2010), monocytes (Muthumani et al., 2011), CRC (Song et al., 2013), melanoma (Jiang et al., 2013; Atefi et al., 2014; Gowrishankar et al., 2015), NSCLC (Xu et al., 2014; Lastwika et al., 2016; Zhang et al., 2017b), breast cancer (Mittendorf et al., 2014; Yang et al., 2017)
	MEK-ERK	↑ multiple myeloma (Liu et al., 2007), NSCLC (Sumimoto et al., 2016), melanoma (Jiang et al., 2013; Liu et al., 2015), bladder cancer (Qian et al., 2008), lymphoma (Yamamoto et al., 2009), dendritic cells (Karakhanova et al., 2010) ↓ melanoma (Atefi et al., 2014), mouse breast cancer (Loi et al., 2016), NSCLC (Liu et al., 2015)
	MAPK14	↑ multiple myeloma (Liu et al., 2007), bladder cancer (Qian et al., 2008), lymphoma (Yamamoto et al., 2009), dendritic cells (Karakhanova et al., 2010)
	RAS	↑ NSCLC (Sumimoto et al., 2016; Coelho et al., 2017; Chen et al., 2017a; Guo et al., 2017), mouse lung (Lastwika et al., 2016), bronchial epithelial cells (Chen et al., 2017a)
	EGFR	↑ NSCLC (Akbay et al., 2013; Chen et al., 2015; Lin et al., 2015; Zhang et al., 2016; Lastwika et al., 2016; Coelho et al., 2017), bronchial epithelial cells (Akbay et al., 2013), breast cancer (Li et al., 2016), head and neck cancer (Concha-Benavente et al., 2016)
	ALK	↑ lymphoma (Marzec et al., 2008; Yamamoto et al., 2009), NSCLC (Ota et al., 2015; Koh et al., 2015)
microRNA	miR-513	↓ cholangiocytes (Gong et al., 2009; Gong et al., 2010)
	miR-155	↓ dermal lymphatic endothelial cells (Yee et al., 2017)
	miR-34a	↓ AML (Wang et al., 2015), NSCLC (Cortez et al., 2015)
	miR-142-5p	↓ pancreatic cancer (Jia et al., 2017)
	miR-93, miR-106b	↓ pancreatic cancer (Cioffi et al., 2017)
	miR-138-5p	↓ CRC (Zhao et al., 2016)
	miR-217	↓ laryngeal cancer (Miao et al., 2017)
	miR-200	↓ NSCLC (Chen et al., 2014; Gibbons et al., 2014), gastric cancer (Xie et al., 2017)
	miR-152	↓ gastric cancer (Xie et al., 2017)
	miR-570	↓ gastric cancer (Wang et al., 2013)
	miR-17-5p	↓ melanoma (Audrito et al., 2017)
	miR-15a, miR-193a, miR-16	↓ malignant pleural mesothelioma (Kao et al., 2017)
	miR-20, miR-21, miR-130b	↑ CRC (Zhu et al., 2014)
	miR-197	↓ NSCLC (Fujita et al., 2015)
Genetic alteration	amplifications	↑ Hodgkin’s lymphoma (Green et al., 2010; Roemer et al., 2016), B cell lymphoma (Green et al., 2010; Twa et al., 2014), NSCLC (Ikeda et al., 2016), SCLC (George et al., 2017), squamous cell carcinoma of the oral cavity (Straub et al., 2016), stomach cancer (Cancer Genome Atlas Research Network, 2014)
	translocations	↑ mediastinal large B cell lymphoma (Twa et al., 2014)
	disruption of 3’ UTR region	↑ multiple tumor types, e.g., T cell leukemia, T and B cell lymphoma, stomach adenocarcinoma (Kataoka et al., 2016)
Post-translational regulation	CMTM6	↑ melanoma, NSCLC, CRC, thyroid cancer, dendritic cells, CML-derived cells, pancreatic cancer, breast cancer (Burr et al., 2017; Mezzadra et al., 2017)
	CMTM4	↑ NSCLC, melanoma, CML-derived cells (Mezzadra et al., 2017)
	CDK4	↓ cervical cancer, breast cancer cells (Zhang et al., 2017a)
	GSK3B	↓ breast cancer (Li et al., 2016)
	B3GNT3	↑ breast cancer (Li et al., 2018)
	CSN5	↑ breast cancer (Lim et al., 2016)

Up and down arrows are used to annotate positive and negative regulators of PD-L1s, respectively.