Essential for normal cell-cell adhesion in the cornified cell layers . Important for proper integrity and mechanical strength of the stratum corneum of the epidermis .
Subcellular locations: Cytoplasm, Cytoplasmic granule
In the stratum corneum of the epidermis, dispersed diffusely throughout the cytoplasm, while in the stratum granulosum, localized within keratohyalin granules  . In granular keratinocytes and in lower corneocytes, colocalizes with calpain-1/CAPN1.
Expressed in skin, thymus, stomach and placenta, but not detected in heart, brain, liver, lung, bone marrow, small intestine, spleen, prostate, colon, adrenal gland, kidney, pancreas, mammary gland, bladder, thyroid, salivary gland and trachea. Weakly expressed in esophagus, tonsils and testis (at protein level). In the skin, strongly expressed in the upper stratum granulosum and lower stratum corneum, but not detected in the upper stratum corneum (at protein level)  . In scalp hair follicles, mainly restricted within the granular and cornified cells surrounding the infundibular outer root sheath, with weak expression in central and proximal outer root sheath (at protein level). Tends to be down-regulated in sporiatic lesions compared to non-lesional skin inthe same patients .