Contributes to the epidermal integrity and skin barrier function. Plays a role in the lamellar granule (LG) secretory system and in the stratum corneum (SC) epithelial cell formation (By similarity). Colocalized with TGOLN2 in the trans-Golgi network. Colocalized with LAMP1 in the lysosome (By similarity). Expressed in the epidermis of the skin. Expressed in epithelial cells of the outermost layer of the stratum granulosum (SG) and hair follicles (at protein level). Defects in TMEM79 may be associated with susceptibility to atopic dermatitis. Atopic dermatitis is a complex, inflammatory disease with multiple alleles at several loci thought to be involved in the pathogenesis. It commonly begins in infancy or early childhood and is characterized by a chronic relapsing form of skin inflammation, a disturbance of epidermal barrier function that culminates in dry skin, and IgE-mediated sensitization to food and environmental allergens. It is manifested by lichenification, excoriation, and crusting, mainly on the flexural surfaces of the elbow and knee.