Based on limited published evidence, GTF3C4 is an essential subunit of the general transcription factor IIIC complex required for RNA polymerase III-mediated transcription of small RNAs including 5S rRNA, tRNA, and VA RNA. It possesses histone acetyltransferase (HAT) activity with specificity for histone H3 1. GTF3C4 facilitates recruitment of TFIIIB and RNA polymerase III through interactions with BRF1, POLR3C, and POLR3F. Recent studies implicate GTF3C4 in cellular senescence 2 and breast cancer prognosis as a histone acetylation writer gene 3.