MAPK3 and cancer: Similarly, pimasertib (MEK1/2 inhibitor) in combination with voxtalisib (mTOR/PI3K inhibitor), also elicited ocular and cardiac toxicities (NCT01390818); CC-90003 (ERK1/2 inhibitor) caused grade 1-3 neurotoxicity (NCT02313012), and GDC-0994 (ERK1/2 inhibitor) in combination with cobimetinib (MEK1/2 inhibitor) caused grade 3 dose-limiting toxicities including myocardial infarction and rash (NCT02457793) in advanced cancer patients34–36.