PTK2B and breast cancer: This result was further confirmed using Cox regression analysis (Fig. 4b) Although analysis of the capacity of high or low expression of PYK2 to predict cancer-specific survival in the total cohort of patients showed a non-statistically significant reduction associated with high expression of PYK2 (χ2 = 1.19, p = ns) (Fig. 4c), the same analysis excluding HER2+/ER−/PR- breast cancer patients resulted in no difference in cancer-specific survival between low and high expression of PYK2 (χ2 = 1.107, p = ns) (Fig. 4d).