The combination of PD (400 μM) and OXA (40 μM) produced a stronger fluorescence intensity of γ-H2AX than that of the single-drug treatment groups in both RKO (Figure 4A) and LoVo (Figure 4B) cells, indicating that PD combined with OXA exerts anti-CRC activity by inducing DNA damage. This evidence concerns the gene H2AX and colorectal carcinoma.