The positivity for the tax gene (S2 Fig) was 93.8% (46/49) in the tumor group and 51.2% (20/39) in the control group, while for the env gene (S3 Fig) it was 57.1% (28/49) in the tumor group and 35.8% (14/39) in the control group. Here, ERVW-1 is linked to neoplasm.