In ErbB2-positive breast cancer cell lines, ShcY317F blocks growth by disrupting cell-cycle progression (Stevenson et al, 1999); in NIH3T3 cells it reduces the RET/PTC2 oncogene transforming activity (Mercalli et al, 2001); in adipocytes it suppresses the IGF-induced proliferation (Boney et al, 2000); moreover, a Shc mutant lacking the CH1 domain that includes Y317, suppresses NIH3T3 transformation induced by the neu oncogene (Li et al, 1999). This evidence concerns the gene PTCH2 and breast carcinoma.