PPIB and skin basal cell carcinoma: Moreover, a topical treatment of basal cell carcinoma (BCC) with new acetylenic retinoid selective for retinoic acid receptor (RAR)-b and c isotypes, tazarotene, revealed more than 50% clinical and dermoscopic regression in 70.8% of BCC and 30.5% healed BCC without recurrences after 3 years of follow-up.