The human genome. (A) Organization of the human genome. Circles represent the approximate proportion of the various sequence categories. Grey circle indicates the whole genome. (B) Gene model with exons, introns, and promoter and interspersed repetitive elements. Pink and red ovals indicate enhancer and promoter; dark blue large boxes, coding exons; light blue smaller boxes, 5′ and 3′ untranslated regions; and green and yellow arrows, SINEs and LINEs, respectively.