OFD1-specific knock-down with siRNA in MM1S cells. (A) OFD1 knock-down with specific siRNA in MM1S cells reveals a time-dependent, but dose-independent, inhibition of OFD1. (B) OFD1-specific inhibition leads to a down-regulation of Hh- and Wnt-related genes at 48 hours. (C) The levels of expression of Gli1, Ptch1, and p-β-catenin proteins, after OFD1-specific knock-down, were quantitated by densitometry and normalized with tubulin.