It is worth noting that, while FF and HF are strong blocks to replication in the absence of DinB, the level of bypass detected in the DinB− cells (28 to 40%) was higher than that seen for the concurrently run positive control m3C (∼10%) or other alkyl lesions (i.e., m1G or m3T) tested previously in AlkB-negative cells [53]. Here, ALKBH1 is linked to hydrops fetalis.