This study has been done to correlate differential Th1/Th2 cell mediated immune responses observed in leprosy with known T cell transcription factors (STAT-4, STAT-6 and CREB) ex vivo along with the effect of M. leprae antigens (MLSA, WCL and PGL-1) on the modulation of these transcription factors. Here, SDHD is linked to leprosy.