PURB and acute myeloid leukemia: Two other proteins of interest that bind to single-stranded DNA in the nucleus are encoded by Purb and Fubp1. In the first case, purine-rich element-binding proteins A and B are implicated in the regulation of gene expression at both transcription and translation levels, the highest levels of PURB being observed in myeloid cells from patients with primary acute myelogenous leukemia displaying risk factors forecasting a poor prognosis [63].