A higher proportion of T > C changes, not embedded in a defined sequence context, has been reported for MMR-deficient tumor samples containing mutations in the lagging strand polymerase Polδ (Shlien et al. 2015), but not in S. cerevisiae and human tumors with a combined MMR and Polε deficiency (Lujan et al. 2014; Shlien et al. 2015). Here, POLD1 is linked to neoplasm.