KRAS and colorectal carcinoma: Because doxycycline did not affect cell proliferation in either KRAS wild-type or KRAS-mutated CRC cells (see Figure S1), the reduced proliferation after overexpression of mutated KRAS may be due to the hyperactivation of the MEK-ERK-cyclin D pathway stimulating senescence by producing p15, p16 and p19 proteins [42].