CSF1R and pancreatic ductal adenocarcinoma: In addition, it has been shown that crosstalk between immune cells and ALDH+ tumor cells is reciprocal, as the targeting of tumor-associated myeloid cells by the inhibition of colony-stimulating factor 1 receptor (CSF1R) resulted in the depletion of the ALDH+ CSC population in pancreatic ductal adenocarcinoma (PDAC) tumors [214,215,216].