In recent years, numerous genetic studies have explored the associations between MMP-2 and MMP-9 polymorphisms and cancer risk across various types of cancer, including head and neck [22,23,24], lung [25,26,27,28], esophageal [29,30,31], breast [32,33,34,35], hepatocellular [36,37], gastric [30,38,39,40], colorectal [41,42,43,44], gallbladder [45,46], cervical [47], bladder [48,49], renal [50], and prostate cancer [51,52,53] in diverse populations. This evidence concerns the gene MMP9 and cancer.