COL4A4 and bladder transitional cell carcinoma: In KICH and HNSC, their tumor’s expression was higher than the normal’s, while the lower expression could be seen in the tumor part rather than the normal part in BLCA and Prostate Cancer (PRAD), etc. The term of the COL4A4 gene, which was increased in the high-grade group compared with the low-grade group, differed in 15 cancer types (Fig. 5j).