The RT-qPCR analysis revealed that GDF15 was expressed in normal bladder epithelial cells and stromal cells with higher levels of GDF15 in HBdSMC and HBdEC, with RT-4 cells having the highest and TSGH-8301 cells having the lowest level of GDF15 among the carcinoma cells (Fig. 1A). The gene discussed is GDF15; the disease is carcinoma.