GRB2 and neoplasm: Our tumor models were slightly different compared to the models published several years ago by other investigators (Figure 1A) [16], where the authors used the MMTV-Neu mouse model with Y1144 (YB) and Y1227 (YD) mutation in ErbB2 to activate specific HER2 signaling pathway - Shc or Grb2, respectively [31].