passages.id: split_8_test_1958_passage
passages.type: progene_text
passages.text: The four known cytochrome P450 3A genes in humans , CYP3A4 , CYP3A5 , CYP3A7 , and CYP3A43 , share a high degree of similarity , consist of 13 exons with conserved exon - intron boundaries , and form a cluster on chromosome 7 .