Normal Bj5Ta cells revealed a significant increment in residual foci after irradiation day 15 (both regimes); whereas cancer cells noticeably tended to have lesser residual foci after irradiation day 15 (Table 3, Figure 5) with A549 being the most resistant with no elevated residual γH2Ax/53BP1 foci at any investigation day or dose. Here, TP53BP1 is linked to cancer.