Complex sentence: The human SMAD3 gene is located on chromosome 15 with location of the cytogenic band at 15q22.33 is composed of 9 exons over 129,339 base pairs.
Split into simpler sentences: The human SMAD3 gene is located on chromosome 15 on the cytogenic band at 15q22.33. The gene is composed of 9 exons over 129,339 base pairs.