CD4 and neoplasm: demonstrated that apCAFs, derived from mesothelial cells by lineage tracing, directly induce naïve CD4+ T cells to differentiate into Tregs in an antigen‐specific manner in pancreatic cancer.[227] Given the substantial heterogeneity and functional diversity of fibroblasts,[228, 229, 230, 231] further comprehensive analyses are essential to fully understand the impact of CAFs on anti‐tumor immunity and ICI responses.