Tumor suppressor which has the ability to inhibit cell growth and be pro-apoptotic during cell stress. Inhibits cell growth in bladder and prostate cancer cells by a down-regulation of HSPB1 by inhibiting its phosphorylation. 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 (PubMed:15731013, PubMed:18931701). Is a negative regulator of ciliogenesis (PubMed:25270598). {ECO:0000269|PubMed:15731013, ECO:0000269|PubMed:18931701, ECO:0000269|PubMed:25270598}. This is the function of ENSG00000139437 (TCHP, trichoplein keratin filament binding).