In comparison, in LNCaP xenografted mouse plasmas, a very high correlation between circulating PSA levels with tumor size (Fig. 6I, r: 0.94, p = 0.0001), as well as a rather good correlation with GDF-15 were observed (Fig. 6H, r: 0.82, p = 0.0583). Here, GDF15 is linked to neoplasm.