Quantitative PCR analysis of osteoclast marker genes. RANKL-dependent expression of osteoclast marker genes in cultures of H1-derived (A) and MSC-iPS1–derived (B) precursors. Cells from day 21 EB cultures were seeded at 105 cells/96-mm well on dentine slices in the absence or presence of RANKL as indicated and harvested 14 days later for RNA isolation and analysis of the osteoclast marker genes cathepsin K (CATK), calcitonin receptor (CTR), and NFATc1 by quantitative reverse-transcription PCR. The data represent the mean ± SD of 3 to 6 wells. *P < .05.