Verification of Psmb10 and Ap4s1 as HDI-suppressed genes. Primary calvarial osteoblasts were cultured in osteogenic medium containing the indicated HDI or DMSO. mRNAs were isolated after 18 hours and subjected to quantitative real-time PCR with primers for Psmb10 (A) or Ap4s1 (B). Values are relative to those obtained from DMSO-treated samples at each time point and represent the mean of three samples. ** denotes p < 0.05 by one-way ANOVA of the HDI-treated sample versus the DMSO-treated sample at that time point.