Structure, function and usage of integrin alpha 6 (CD49f): A comprehensive review.

Integrin alpha-6 (α6ITG, CD49f) has long been considered one of the most reliable markers of stemness, yet emerging evidence challenges this view by revealing its broader role in niche accessibility and survival. As a laminin receptor, α6ITG mediates cellular interactions and participates in signal transduction pathways that help maintain cellular phenotype. Its expression allows for the identification and purification of stem cells from heterogeneous populations. Because α6ITG expression is highly sensitive to environmental cues, it also serves as a sensor of culture conditions and cryopreservation stress, with potential use in biobanking and regenerative medicine. This marker holds significant potential; it may be one of the few markers consistently expressed in all stem cells, potentially qualifying it as a common "stemness" marker. Additionally, the therapeutic implications of α6ITG knockdown using antibodies may greatly influence future cancer treatments. Elevated expression in cancer correlates with growth, invasion, and poor prognosis. The aim of this review is to explore the biological and translational importance of α6ITG in stem cell and cancer biology.