Trichostatin A (TSA) is a potent and non-competitive reversible inhibitor of histone deacetylases (HDAC) with a Ki of 3.4 nM. In HeLa cells, TSA blocked cell cycle progression at G1 and induced a 12-fold increase in intracellular levels of gelsolin. In cells latently infected with HIV-1, TSA induced the transcriptional activation of the HIV-1 promoter, which resulted in a marked increase in virus production. In NIH 3T3 cells, TSA induced reversion of oncogenic ras-transformed cells to a normal morphology. In Jurkat cells, TSA inhibited IL-2 gene expression and displayed immunosuppressive activity in a mouse model. Induces increased acetylation of GATA4, a cardiac-specific transcription factor and increases cardiac muscle cell differentiation. In normal fibroblasts, induced Friend cell differentiation and inhibited the G1 and G2 phases of the cell cycle. Trichostatin A is a useful tool for induction of hyperacetylation of cellular histones and for further elucidation of their role in gene expression. A glucoside analog of Trichostatin A is also offered as Trichostatin C (sc-202369). Trichostatin A is an inhibitor of TERT, HDAC1, HDAC4 and HDAC6.