Among betel-nut consumers in our cohort, subjects with ICAM-1 polymorphic rs3093030, rs5491, rs281432, or rs5498 genes and who smoked had corresponding 11.99- (95% CI: 4.134–34.785), 14.27- (95% CI: 2.851–71.452), 13.77- (95% CI: 4.586–41.318), and 9.93-fold (95% CI: 3.516–28.058) higher risks of having oral cancer compared to betel-nut chewers with the WT gene who did not smoke (Table 5). Here, ICAM1 is linked to lip and oral cavity carcinoma.