Tumor suppressor which has the ability to inhibit cell growth and be pro-apoptotic during cell stress. May act as a 'capping' or 'branching' protein for keratin filaments in the cell periphery. May regulate K8/K18 filament and desmosome organization mainly at the apical or peripheral regions of simple epithelial cells (By similarity). Is a negative regulator of ciliogenesis (By similarity). Interacts specifically with keratin proteins including, KRT5, KRT6A, KRT8, KRT14, KRT16 and KRT18. Interacts with KCTD17 (By similarity). Expressed in all tissues examined, including brain, liver, small intestine, large intestine, lung and heart. Found concentrated in tubular structures within hepatocytes, and in the apical cortical region and desmosomes of the apical junctional domain in enterocytes of the small intestine. In the hair follicle, localized at the outer root sheath. Also expressed in blood vessels (at protein level). Ubiquitinated. Ubiquitination by the BCR(KCTD17) E3 ubiquitin ligase complex results in proteasomal degradation, and induces ciliogenesis. Belongs to the TCHP family. Truncated N-terminus.