These findings are consistent with the idea that MenaCalc, which represents the abundance of Mena isoforms lacking the 11a exon, is more associated with pro-metastatic phenotypes than either total Mena or Mena11a levels, and provides insight into why MenaCalc, but not Mena or Mena11a levels, are associated with poor clinical outcome in appropriately powered analyses of multiple breast cancer patient cohorts34, 35. This evidence concerns the gene EGFR and breast cancer.