Involved in cell adhesion. Contributes to integrin activation. When coexpressed with talin, potentiates activation of ITGA2B. Required for normal keratinocyte proliferation. Required for normal polarization of basal keratinocytes in skin, and for normal cell shape. Required for normal adhesion of keratinocytes to fibronectin and laminin, and for normal keratinocyte migration to wound sites. May mediate TGF-beta 1 signaling in tumor progression. Interacts with the cytoplasmic domain of integrins ITGB1 and ITGB3. Constituent of focal adhesions. Localized at the basal aspect of skin keratinocytes, close to the cell membrane. Colocalizes with filamentous actin. Upon TGFB1 treatment, it localizes to membrane ruffles. Expressed in brain, skeletal muscle, kidney, colon, adrenal gland, prostate, and placenta. Weakly or not expressed in heart, thymus, spleen, liver, small intestine, bone marrow, lung and peripheral blood leukocytes. Overexpressed in some colon and lung tumors. In skin, it is localized within the epidermis and particularly in basal keratocytes. Not detected in epidermal melanocytes and dermal fibroblasts. By TGFB1. The FERM domain is not correctly detected by PROSITE or Pfam techniques because it contains the insertion of a PH domain. The FERM domain contains the subdomains F1, F2 and F3. It is preceded by a F0 domain with a ubiquitin-like fold. The F0 domain is required for integrin activation and for localization at focal adhesions. The disease is caused by variants affecting the gene represented in this entry. Although most FERMT1 mutations are predicted to lead to premature termination of translation, and to loss of FERMT1 function, significant clinical variability is observed among patients. There is an association of FERMT1 missense and in-frame deletion mutations with milder disease phenotypes, and later onset of complications (PubMed:21936020). Belongs to the kindlin family.