VAV1 and breast neoplasm: The question of whether Vav1 affects Akt1 activation in breast tumor cells with phenotypes other than triple negative was addressed in the breast cancer‐derived cell lines BT‐474, MCF7, and MDA‐MB‐453, which represent the most frequent subtypes of breast tumors and express Vav1 to a variable extent (Grassilli et al., 2014; Fig. 3A).