Interestingly, highly malignant tumor cell line 4T1luc2, genetically unstable, p53null, with complex aneuploid karyotype [60,61,62], and two of the subclones, 4T1luc2_rtTERT_C6 and 4T1luc2_rtTERT_H9, appeared to be relatively genomically stable (few γ-H2AX foci; Figure 7A, panel I, and Figure 7A, panel II,III,E). This evidence concerns the gene H2AX and neoplasm.