Background: Pol Iota is a DNA polymerase involved in DNA repair and translesion DNA synthesis. Pol Iota is a member of the Rad30 family of DNA polymerases which exhibit low fidelity when replicating undamaged DNA, and in this context may play a role in the hypermutation of immunoglobulin genes. Pol Iota is also known as RAD30B and is a paralog of RAD30A, also known as Pol eta.