PTK2 and breast cancer: In agreement with FAK amplification status, a higher proportion of basal-like breast cancers in this cohort had higher levels of FAK mRNA expression (mRNA z-score threshold = ± 2, for high and low respectively) (chi-square test, p < 0.0001) (Fig. 1c), and basal-like breast cancers exhibited the highest mean log2(fold change) of 1.414 (Fig 1d).