Figure 3. Trio isoforms. In addition to its complex structure, the trio gene can encode several isoforms as a result of alternative splicing. Five isoforms (TrioA to E) that differ in their C-terminus have been described to be specific of the nervous system, with TrioC/Solo expressed only after birth in the Purkinje cells of cerebellum. In addition, a sixth, oncogenic isoform of Trio, named Tgat, has been isolated from ATL (adult-T cell leukemia) patients.