Expression levels of four crucial FAGs between tumor and normal tissue were demonstrated in Additional file 9: Figure S9, which indicated that G6PD, TFRC and SQLE were significantly upregulated in BLCA, while CRYAB was significantly downregulated when compared with normal tissues (all P < 0.05) (Additional file 9: Figure S9A) and paired non-tumor tissues (all P < 0.05) (Additional file 9: Figure S9B). The gene discussed is G6PD; the disease is bladder transitional cell carcinoma.