Several studies have investigated the relationship between the single nucleotide polymorphisms (SNP, −842G/C, rs2233678) in the PIN1 promoter region and risk of cancers, such as breast cancer [14], [15], lung cancer [16], esophageal carcinoma [17], hepatocellular carcinoma [18], nasopharyngeal carcinoma [19], laryngeal squamous cell carcinoma [20], and squamous cell carcinoma of the head and neck [21]. This evidence concerns the gene PIN1 and cancer.