Breast cancer patients demonstrated significantly elevated serum levels of ALT (6.6 ± 0.55 U/mL vs. 4.2 ± 0.45 U/mL in controls), LDH (16.8 ± 1.4 U/mL vs. 9.4 ± 0.78 U/mL), and cancer antigen 15-3 (CA15-3; 160 ± 13.33 U/mL vs. 33.5 ± 2.79 U/mL), alongside a marked reduction in AST (2.6 ± 0.22 U/mL vs. 5.8 ± 0.54 U/mL), with all differences statistically significant (P ≤ 0.05). The gene discussed is GPT; the disease is breast cancer.