PTPN11 and melanoma: A screen of human melanoma and colon carcinoma biopsy specimens showed that most CD31+ endothelial cells are p‐EphrinB+ (86 and 94%, respectively), p‐SHP2+ (68 and 76%, respectively), p‐TIE2+ (83 and 82%, respectively), and Ang2+ (92 and 83%, respectively) (Fig 2A).