GDF15 and prostate cancer: However, through surveying our collated RNA-seq data, we found that the levels of GFRAL mRNA in benign prostate tissues, primary prostate cancer, and metastatic CRPC samples are very low, with mean TPM values of 0.22, 0.13, and 0.13, respectively, as opposed to 134, 459, and 127, respectively, for GDF15 (S3 Fig).