GDF15 and prostate cancer: To date, proprotein convertase, subtilisin/kexin-type (PCSK) 3, 5, and 6 have been recognized as proteases able to cleave pro-GDF15 in in vitro and in vivo studies on cardiomyocytes, heart, and prostate cancer (Couture et al., 2017; Li et al., 2018).