KIAA0101 is a PCNA-binding protein that acts as a regulator of DNA repair during DNA replication. Following DNA damage, the interaction with PCNA is disrupted, facilitating the interaction between monoubiquitinated PCNA and the translesion DNA synthesis DNA polymerase eta (POLH) at stalled replisomes, facilitating the bypass of replication-fork-blocking lesions. This protein also acts as a regulator of centrosome number. Recombinant human KIAA0101 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.