PTK7 and breast cancer: Analysis of the 1097 tumor tissues and 113 normal tissues of BC in the TCGA database showed that the median level of PTK7 mRNA, Log2 (FPKM-UQ + 1), in tumor tissues (18.37) was significantly higher than that in normal tissues (17.64; p = 3.67 × 10−11; Figure 1A, left panel).