Pyroamide is a histone decetylase inhibitor (HDCi), a novel class of anti-neoplastic agent that acts by enhancing acetylation of histones, promoting uncoiling of chromatin and activation of genes implicated in the regulation of cell survival such as poliferation, differentiation and apoptosis. Pyroamide is known to potently inhibits affinity purified HDAC1. Also inhibits the growth of tumor cells in vitro and in vivo. Induces p21/WAF1 expression in tumor cells.