NOS3 and hepatocellular carcinoma: In the Italian multicenter, retrospective ePHAS (eNOS polymorphisms in HCC and sorafenib) study, the prognostic value of three eNOS polymorphisms, eNOS-786 T > C in the promoter region, a 27bp variable number of tandem repeats in intron 4 (eNOS VNTR 4a/b) and eNOS + 894 G > T in exon 7 were analyzed in terms of progression-free survival (PFS) and OS.