Promotes cell proliferation, G1/S cell cycle progression and induces expression of the cell cycle regulator CCND1 (PubMed:30009832). Regulates proliferation induced by pro-inflammatory cytokine response via activation of NFKB1 and PI3K/AKT signaling pathways (PubMed:30009832). Homodimer. Does not colocalize with TGM1. Expressed in the basal skin layer (at protein level) (PubMed:30009832). Squamous epithelia cell-specific. Expressed in the esophagus (periphery of the cells of the granular and the upper spinous layers), foreskin (granular and lower cornified cells), scalp skin (granular layer), inner root sheath of the hair follicle and in primary keratinocytes (at protein level). Expressed in the squamous epithelium of the cervix, esophagus, foreskin and larynx. Expressed in the fetal bladder and scalp skin. Expressed at very low levels in the lung, kidney, uterus, skeletal muscle, heart and fetal brain. Undetectable or barely detectable in esophageal and oral squamous cell carcinoma compared with the matched adjacent normal esophageal mucosa. Undetectable or barely detectable in larynx and esophagus from patients with pH-documented laryngopharyngeal reflux (LPR). Up-regulated after heat shock, ponasterone A and deoxycholic acid (PubMed:15896671, PubMed:16640557). Induced in response to pro-inflammatory cytokines (PubMed:30009832). The EF-hand is necessary for the colony survival activity to protect cells from death induced by exposure to DCA. Disease susceptibility is associated with variants affecting the gene represented in this entry. CRNN expression is increased in psoriasis patients suggesting a potential role in disease pathogenesis. Belongs to the S100-fused protein family.