XRCC1 and skin neoplasm: We observed that the inverse association of XRCC1 399Gln on SCC risk was significantly stronger among the individuals with a family history of skin cancer (P for trend, 0.001) than women without family history of skin cancer (P for trend, 0.71; P for ordinal interaction, 0.01; P for nominal interaction, 0.02) (Table 3).