RASA2 and Noonan syndrome: We focused on RASA2 (RAS p21 protein activator 2), a gene recurrently mutated by loss-of-function mutations in the RASopathy Noonan syndrome (41), and in a number of other malignancies (42, 43), as all 4 guides scored in our screen for the CMS cell line (Fig. 5C) and one for WSU-AML (Supplemental Figure S5F).