TGFB1 and neoplasm: In pancreatic ductal adenocarcinoma (PDAC), TGF-β secreted by TAMs activates the Smad2/3/4-Snail axis, driving EMT and liver metastasis.4 Similarly, TAMs from cancer stem cells (CSCs) contribute to tumor heterogeneity and treatment resistance, suggesting that there is bidirectional crosstalk between CSCs and TAMs in TME maintenance.8