SRC and breast cancer: FOXM1 is also a substrate of the tyrosine kinase c-Src (Fig. 1), and recent work has shown that mutation of either of two critical tyrosines (Y239, Y517) prevents these phosphorylations and FOXM1 nuclear translocation, and greatly impairs FOXM1 activity, breast tumorigenesis, and cancer progression in a luminal B breast cancer model [28].