ChIP was performed on total thymocytes from WT or HDAC3-cKO using the SimpleChIP Enzymatic Chromatin IP kit, (Cell Signaling, #9002) per manufacturer’s guidelines. Chromatin was incubated with α-acetyl Histone 3 antibody (Millipore) and control antibodies (Cell Signaling, #9002) overnight at 4°C with rotation. Extracted DNA was analyzed by real-time PCR using previously published primer sequences spanning the RORC promoter (26 (link)).