MAPK3 and malignant colon neoplasm: Expression of the leukotriene D4 receptor (CysLT1) is increased in colorectal adenocarcinomas and leukotriene D4 (LTD4) and LTB4 stimulate colon cancer cell proliferation by activating ERK1/2 (Paruchuri et al, 2002, 2006; Nielsen et al, 2003, 2005; Ohd et al, 2003).