Although in the TMA there were no differences between the CrkL staining and the PR(−) versus PR(+) and ER(−) versus ER(+) status (p = 0.27 and 0.11, respectively), following studies will have to examine the relationship between the breast cancer subtype and the levels of the soluble CrkL in the patients’ sera. This evidence concerns the gene ESR1 and breast carcinoma.