XRCC1 and cancer: Although, statistically, no significant association between disease (cancer, precancer) and polymorphism was observed (data not shown) [16] but Figure S1 in File S1 shows that there are some definite SNPs which can control number of diseased and healthy individuals in the total population, for example removal of SNP2 (XRCC1, codon 399, Arg/Gln) decreases the case specific genotypic fraction and removal of SNP4 (XPC, Codon 939, Lys/Gln) decreases the control specific genotypic fraction which corroborates partially our previous report that polymorphism at XRCC1 increases risk of cancer [16].