EGFR and breast carcinoma: SHP-1 associates directly with the EGFR in human mammary carcinoma cells through phosphotyrosine 1173 on the EGFR (Keilhack et al. 1998; Tomic et al. 1995), while SHP-2 mediates the dephosphorylation of tyrosine 992 (Agazie and Hayman, 2003).