Two of the features, RPS4Y1 and DDX3Y, are already Y chromosome-associated, and HLA-DRB5 and TPPP3 have been reported as being associated with GBM [43,44] with respect to prognosis and the epithelial–mesenchymal transition, respectively, albeit not in serum biospecimens as of yet. Here, TPPP3 is linked to glioblastoma.