ERBB2 and neoplasm: For example, the following crosses all resulted in accelerated tumor development: MMTV-MAT × MMTV-neu (Rudolph-Owen et al., 1998), MMTV-Vegfa × MMTV-neuYD (Oshima et al., 2004), MMTV-Akt1*T308D*S473D × MMTV-PyMT (Hutchinson et al., 2001).