Table 1.

scRNA-seq analyses to dissect the molecular complexity of TME in PDAC: a historical summary.

Year	Molecular analysis Samples	Resulting evidence	Reference
2018	scRNA-seq IPMN patients	Low-grade IPMNs are enriched for CTLs and CD4+ effector T cells compared to high-grade IPMNs	Bernard et al. (50)
2019	scRNA-seq PDAC patients	Three patient clusters identified: cluster 3 vs. clusters 1 and 2 showed high expression of proliferation markers and worse survival; enrichment of cell cycle, DNA replication, and DNA repair pathways and depletion in several immune/T-cell activation gene sets	Peng et al. (51)
2019	scRNA-seq PDAC patients, murine models	Two immune clusters identified: 1. Myeloid cluster, composed of resident macrophages, M2 macrophages, classic monocytes, cDC1, and two types of Langerhans-like dendritic cells 2. Lymphoid cluster, composed of CD8+ T cells, CD4+ T cells, Tregs, proliferating Tregs, and NK cells	Elyada et al. (52)
2019	scRNA-seq Murine models of PDAC (KIC, KPC, KPfC)	Two immune clusters identified: 1. Expression of several genes associated with chemokines and inflammation 2. Enriched in MHC-II-associated genes	Hosein et al. (53)
2020	scRNA-seq Human primary tumors and metastatic lesions	Two tumor-infiltrating lymphocyte clusters identified, with no difference between primary tumors and metastases: 1. High levels of markers associated with activation and exhaustion 2. Antigen-inexperienced T cell Two macrophage clusters identified: 1. M2 polarization, expression of genes associated with extracellular matrix production and wound healing processes 2. Expression of genes associated with antigen presentation.	Lin et al. (54)