Mechanistically, KRAS mutation-induced activation of YAP enables PDAC cells to release IL-4, IL-6, IL-13, MCP-1 and CSF-1, which promote the recruitment of tumor-associated macrophages (TAMs) into tumors and induce them to proliferate and polarize into an M2-like phenotype [45] (Figure 1). This evidence concerns the gene KRAS and neoplasm.