COL18A1 and cancer: In Elyada’s scRNA-seq analysis, ductal cancer cells in human PDAC were clustered in two major subtypes: the classic (by TFF1, TFF2, LYZ, VSIG2, and CEACAM6 marker genes) and secretory (by SPP1, CLU, CTGF, and COL18A1 marker genes) subtypes.