MEK inhibition also reversed RASopathy phenotypes in PTPN11- and NRAS-associated zebrafish models of NS (Bonetti et al., 2014; Runtuwene et al., 2011), BRAF- and MAP2K1-associated zebrafish models of CFC (Anastasaki et al., 2009), and ARAF-associated zebrafish models of CCLA (Li et al., 2019). Here, MAP2K1 is linked to cardiofaciocutaneous syndrome.