KRAS and Costello syndrome: This class of congenital developmental disorders came to be referred to as “RASopathies.” It encompasses syndromes such as Noonan syndrome (caused by mutations in RAF1 [MIM611553], PTPN11 [MIM151110], SOS1 [MIM610733], KRAS [MIM609942] or SHOC2 [MIM607721]), Costello Syndrome (HRAS, MIM218040), cardiofaciocutaneous syndrome (BRAF, MAP2K1/2, KRAS), neurofibromatosis type I (NF1, MIM162200), capillary malformation‐arteriovenous malformation (RASA1, MIM139150), Noonan syndrome 13 (MAPK1, MIM176948), and Noonan syndrome 14 (SPRED2, MIM619745; Motta et al, 2021).