GDF15 and prostate cancer: Collating the RNA-seq data from 500 primary tumors in TCGA cohort and the RNA-seq data of 159 metastatic CRPC samples from the SU2C project (n = 51) [32], the PROMOTE study (n = 74) [33], and the Beltran cohort (n = 34) [34] showed significantly higher levels of GDF15 mRNA in primary prostate cancers compared to metastatic CRPC samples (Fig 3A).