Although the percentage of female smokers used in this study was very low (13.1%) compared to the male smokers (59.9%), it was intriguing to find a significant high-risk difference in the genotypic and the allelic distribution of XPA rs3176751 in female smokers, suggesting a possible interference of CS in disease development among women, as reported previously for innate immune genes in acute respiratory distress syndrome [40] and human papillomavirus [41]. This evidence concerns the gene XPA and Cowden syndrome 1.