After Castelli et al. [20] first assessed the correlation between the HLA-G 14-bp Ins/Del variation and bladder cancer in 2008, a growing number of molecular epidemiological case–control studies have been carried out in different populations to investigate the association of the HLA-G 14-bp Ins/Del variant with different types of cancers [11,13,21–24]. The gene discussed is HLA-G; the disease is cancer.