In addition to DNA repair, it has been shown that E. coli AlkB and the human AlkB homologue hABH3 may be involved in RNA repair. When expressed in E. coli both AlkB and hABH3 reactivate methylated RNA bacteriophage MS2 in vivo. This illustrates that direct repair may be an important mechanism for maintenance of RNA in living cells [4] . RNA repair proceeds by the same mechanism as DNA repair. Repair of damaged RNA was previously considered very unlikely, due to the natural redundancy of RNAs in a cell [8] . However, RNA is essential for cell function: unrepaired RNA can lead to miscoded or truncated proteins, and alkylated RNA could signal cell cycle checkpointing or apoptosis [9] . Consequently the occurrence of RNA repair does not come as a great surprise. The mechanism of direct reversal of methylation as used by AlkB homologues is particularly important for RNA repair, as it means that single-stranded regions may be repaired without introducing strand breaks. Repair of alkylation damage in DNA and RNA has recently been reviewed [10] .