The result revealed that HERV-K and specifically the Env gene could be expressed in basal tumors subtypes IDC rather than the other types of breast tumors [96], in which analysis of HERV Env cDNA extracted from four types of breast tumors depicted that almost 97% of the Env cDNAs belonged to type I HERV-K102 [140]. The gene discussed is ERVW-1; the disease is breast neoplasm.