Notably, chlorpyrifos (CPF) and other widely used organophosphate insecticides associated with exposure-dependent cancer risk activate signaling pathways similar to those following muscarinic receptor activation [137]; in H508 colon cancer cells, CPF increased EGFR phosphorylation and downstream activation of ERK1/2 [138]. This evidence concerns the gene MAPK3 and malignant colon neoplasm.