MAPK3 and colorectal neoplasm: When ERK5 was inhibited, the expression levels of both Mki67 and Lgr5 were both significantly reduced in ERK1/2-deficiency organoids; although they did not show any changes in the condition without ERK5 alteration, targeting both ERK1/2 and ERK5 showed inhibition of colorectal tumor cell proliferation, which was more pronounced when simultaneous suppression of ERK1/2 and ERK5 50.