Decreased levels of hemoglobin (Hb), which are often observed in patients with malignant tumors [16,17,18,19]; alkaline phosphatase (ALP), which reflects bone metabolic turnover, osteoblast activity, and osteogenesis in bone tissue [20,21,22,23]; and lactate dehydrogenase (LDH), which promotes energy metabolism in tumor cells [24,25], are also useful serum markers for predicting the prognosis of patients with malignant tumors. This evidence concerns the gene GSTM1 and cancer.