SPON1 and prostate cancer: Among them, we focused on three genes which appeared to be up-regulated in the RNA-Seq analyses: S100A16, a member of the S100 calcium-binding protein family up-regulated in many cancers [37] and promoting cell migration and metastasis in prostate cancer [38]; Spondin-1 (SPON1), a protein of the extracellular matrix which is up-regulated in an orthotopic model in mice of PC3-derived tumors that frequently metastasized [39] and PlexinA2 (PLXNA2), a semaphorin receptor up-regulated by the TRMPSS2-ERG fusion in metastatic cancers [40].