PPARGC1A and neoplasm: BHLHE40 has been reported to have tumor suppressive functions (6, 9, 10, 42, 43, 44) and has been shown to affect energy metabolism by regulating PGC-1α, SREBP-1c, PKLR, PCK2, FASN, and PPARγ (11, 12, 13, 14, 15, 16).