PTPN11 and pancreatic neoplasm: Moreover, in an isogenic pancreatic cancer cell line with CRISPR-Cas9-mediated knockout of SHP2, tyrosyl phosphorylation of endogenous KRAS Q61H was observed even in the absence of EGF treatment, which is consistent with the notion that SHP2 is involved in dephosphorylating endogenous KRAS (Fig. 3i).