Thus far in our investigation, we have determined time-points of T cell proliferation through CFSE analysis on both whole spleen and purified T cell samples. Additionally, we have observed that active vitamin D added directly to stimulated splenocytes inhibited T cell function in a dose dependent manner by suppressing IFN-γ (measured by ELISA). The goal this semester was to determine if T cells produce CYP24A1 upon activation and if 1,25(OH)2D3 regulates CYP24A1 mRNA expression.