Therefore, our finding of a connection between the expression of HERV-Kenv and that of SF2/ASF reinforces the possibility that the expression of HERV-Kenv in many tumors [6,51,63,64,65,66] and in HIV-positive persons [67,68] is more that the mere expression of an innocent bystander during diseases such as cancer and HIV infection. The gene discussed is SRSF1; the disease is cancer.