PTPN11 and cancer: Early ultrasound screening has also identified fetuses carrying recurrent and rare NS1 variants as well as germline derived sporadic cancer variants that might have been recognized as NS1 cases if they had further completed development (Croonen et al., 2013; Hakami et al., 2016; Leach et al., 2019; Lee et al., 2009; Mason‐Suares et al., 2017).