PTPN11 and juvenile myelomonocytic leukemia: In vivo, Benjamin Neel, PhD and his group created a mouse model of an NS‐causing PTPN11 GOF mutation (Araki et al., 2004) and found that the Ptpn11 protein product, SHP2, increased the risk of JMML (Mohi et al., 2005) and caused abnormal cardiac valvulogenesis (Araki et al., 2009).