PTPN11 and acute lymphoblastic leukemia: Somatic mutation of genes, which activate the Ras pathway are recurrently found in ALL and include integral components of the pathway, upstream activators, and regulatory proteins and include NRAS, KRAS, BRAF, FMS-related tyrosine kinase 3 (FLT3), protein tyrosine phosphatase, non-receptor type 11 (PTPN11), casitas B lineage lymphoma (CBL), and NF1. An overview is shown in Figure 2.