Research in the Laboratory of Chemical Biology (LCB), for which Dr Grollman serves as Director, focuses on the biological consequences of DNA damage with specific reference to molecular mechanisms of DNA replication, mutagenesis, and DNA repair. Research in the LCB was instrumental in establishing the mechanism of action of bleomycin and in defining an important error-avoidance pathway that protects cells against mutations resulting from miscoding effects of oxidative DNA damage. He and his collaborators established the three-dimensional structures of DNA glycosylases and DNA polymerases bound to site-specifically modified DNA, thereby correlating the molecular structure of damaged DNA with enzymatic function. Current research focuses on molecular and cellular mechanisms involved in the nephrotoxicity of the human carcinogen, aristolochic acid.