Table 1.

Summarized Characteristics of IL-30 to IL-40

Cytokine	Other names	Gene superfamily	Chromosome location	Receptor	Functions	Main human expression tissuesa	Producing cells	Immune cells responding	Potential role in disease	In-depth reviews
IL-30	p28, IL-27p28b	IL-12	16p12.1	IL-27Rα	Suppression of IL-17A production, anti-inflammatory	Placenta, BM, liver, stomach, skin, testis	Monocytes, macrophages, DCs	T cells	Prostate cancer, breast cancer	Di Carlo (2014)
IL-31	None	IL-6	12q24.31	IL-31RA/OSMRβ	Pruritus, proinflammatory	BM, tonsil, spleen, skin	Eosinophils, CD4+ T cells	Epithelial cells, monocytes	Pruritic atopic dermatitis, airway hypersensitivity, IBD	Zhang and others (2008)
IL-32	NK4	None	16p13.3	Unknown	Angiogenesis, IL-2 production in BM, proinflammatory	Appendix, lung, duodenum, small intestine	Monocytes, T cells, NK cells, epithelial cells	Monocytes, macrophages, BM stroma	Cancer, tuberculosis, influenza virus A infection, RA, ulcerative colitis, Crohn's disease, chronic obstructive pulmonary disease	Khawar and others (2016); Sloot and others (2018)
IL-33	NF-HEV, IL-1 F11	IL-1	9p24.1	ST2	Alarmin, proinflammatory	Skin, stomach, cervix, endometrium, nasopharynx, bronchus	Endothelial cells, epithelial cells, fibroblast, mucosal epithelium	T cells, mast cells, eosinophils, basophils, ILC2s	Asthma, IBD	Liew and others (2016)
IL-34	C16orf77	None	16q22.1	CSF-1R, PTP-ζ, CD138	Myeloid cell proliferation, anti-inflammatory	Spleen,c skinc	Keratinocytes, neurons, Tregs, monocytes, macrophages, DCs	Macrophages, monocytes, Langerhans cells, microglia, kupffer cells, DCs	Osteoporosis, lupus, periodontal disease, Hepatitis B, RA, transplant rejection, lung cancer, fibrosis	Guillonneau and others (2017)
IL-35	None	IL-12	3q25.33 (IL12A); 19p13.3 (EBI3)	IL-12Rβ2/IL-12Rβ2; gp130/gp130; IL-12Rβ2/gp130	Prevents Th1 and Th17 cell proliferation, induces Treg/Breg polarization, anti-inflammatory	Placenta, spleen,c	Tregs, Bregs,	Macrophages, T cells	Multiple sclerosis, diabetes, colitis, Hodgkin's lymphoma, lung cancer	Choi and others (2015)
IL-36α IL-36β IL-36γ IL-36RA	FIL1ɛ/IL-1 F6, FIL1η/IL-1 F8, IL-1 F9, FIL1δ/IL-1 F5	IL-1	2q14.1	IL-36R	Th1 responses, proinflammatory	Skin, esophagus, tonsil	Keratinocytes, mucosal epithelial cells, monocytes, macrophages, Langerhans cells, CD4+ T cells	Epithelial cells, macrophages, DCs, T cells, B cells, plasma cells	DITRA,d lesional psoriasis, tuberculosis, IBD	Gabay and Towne (2015)
IL-37	FIL1ζ, IL-1 F7	IL-1	2q14.1	IL-18Rα	Anti-inflammatory	Skin	Epithelial cells, keratinocytes, monocytes, NK cells, B cells	Epithelial cells, fibroblasts, monocytes, macrophages, DCs, T cells	SLE, RA, IBD, ankylosing spondylitis, Graves' disease, HIV infection, coronary artery disease	Jia and others (2018)
IL-38	IL-1 F10, FIL1θ	IL-1	2q14.1	IL-1R; IL-36R; IL-1RAPL1	Blocking of IL-36, anti-inflammatory	Skin	Epithelial cells, B cells	Epithelial cells, macrophages, DCs, B cells, plasma cells	RA, atherosclerosis, cardiovascular disease, SLE, hidradenitis suppurativa, Hepatitis B, diabetes, asthma, fibrosis, lung cancer	Garraud and others (2018); van de Veerdonk and others (2018)
IL-39	None	IL-12	12q13.3 (P19); 19p13.3 (EBI3)	Unknown	Proinflammatory	Spleen	Macrophages, DCs, B cells	Neutrophils	Lupus	None
IL-40	C17orf99	None	17q25.3	Unknown	Involved in IgA production, B cell homeostasis and development	BM, fetal liver	B cells, BM stroma	B cells	B cell lymphoma	None

^aData from protein atlas of human expression (www.proteinatlas.org; Uhlen and others 2015).

^bIL-30 is a subunit of IL-27 but exhibits activity by itself.

^cRNA expression.

^dDeficiency of IL-36 receptor antagonist is a disease caused by the lack of functional IL-36ra.

CSF, colony stimulating factor; DCs, dendritic cells; DITRA, deficiency of IL-36 receptor antagonist; IBD, inflammatory bowel disease; IL, interleukin; NF-HEV, nuclear factor in high endothelial venules; NK, natural killer; OSMRβ, oncostatin M receptor beta; RA, rheumatoid arthritis.