NME1 and head and neck squamous cell carcinoma: Similarly, γ-H2AX-positive and NME1-positive foci were absent from nuclei of Tu167 (head-neck squamous cell carcinoma; HNSCC) cells prior to induction of DSBs, but were strongly induced following treatment with the DSB inducer bleomycin nuclear foci that stained positively for the DSB biomarker γ-H2AX (Figure 1D,E).