HTLV-II is a type of human retrovirus that belongs to the HTLV (Human T-cell Lymphotropic Virus) family. It is primarily transmitted through sexual contact, blood transfusions, and from mother to child during childbirth or breastfeeding. While many people infected with HTLV-II may not show symptoms, it can be associated with certain health issues, including neurological disorders. Unlike its more well-known counterpart, HTLV-I, which is linked to specific cancers and diseases, the clinical significance of HTLV-II is less clear. Research is ongoing to better understand its effects on health and its potential role in various conditions.