Transcription factor that plays an essential role in both trophoblast giant cell differentiation and in cardiac morphogenesis (By similarity). Binds the DNA sequence 5'-NRTCTG-3' (non-canonical E-box) (By similarity). Acts as a transcriptional repressor of SOX15 (By similarity). In the adult, could be required for ongoing expression of cardiac-specific genes (PubMed:9931445). {ECO:0000250|UniProtKB:Q64279, ECO:0000269|PubMed:9931445}. This is the function of ENSG00000113196 (HAND1, heart and neural crest derivatives expressed 1).