differentiated embryo chondrocyte expressed gene 1, enhancer-of-split and hairy-related protein 2, stimulated by retinoic acid gene 13 protein, BHLHE40, Clast5, class E basic helix-loop-helix protein 40, differentially expressed in chondrocytes 1, HLHB2, DEC1, class B basic helix-loop-helix protein 2