Differential expression of Vdr in the subsets of CD4+ T cells. A, mRNAs were isolated from different subsets of CD4+ T cells and subjected to real-time RT-PCR analysis. Relative mRNA expression was compared by setting the lowest expression amount to an arbitrary value of 1. iTreg, inducible Treg cells; nTreg, natural Treg cells. B, naive CD4+ T cells were cultured with TGFβ and IL-6. mRNAs were isolated at each time point and subjected to real-time RT-PCR. C, WT and RORα-, RORγt-, and STAT3-deficient mice were differentiated into Th17 cells, and mRNAs from these cells were subjected to real-time RT-PCR analysis. Data represent the means ± S.E. of at least three independent experiments.