There are two isoforms that code for actins in the smooth muscle tissue: ACTG2 codes for the largest actin isoform, which has nine exons, one of which, the one located at the 5' end, is not translated.
Existen dúas isoformas que codifican actinas do músculo liso: ACTG2 codifica a isoforma máis longa de actina, que ten nove exóns, un deles, o situado no extremo 5', que non se traduce.