SREBF1c is the isoform transcribed from the SREBF1 gene encoding the transcription factor mainly responsible for the expression of lipidogenic genes, while SREBF2 encodes the transcription factor of the genes encoding the enzyme of the MVA pathway including the DHCR7, that catalyzes the production of cholesterol from 7-dehydrocholesterol and is the causative gene for Smith-Lemli-Opitz syndrome (SLOS, OMIM #270400) [9]. This evidence concerns the gene SREBF1 and Smith-Lemli-Opitz syndrome.