IGF2 and transitional cell carcinoma: The presence of regional lymph node metastasis was also associated with decreased IGF-2 gene methylation frequency, i.e., in the cancer tissues from patients with lymph node metastasis, the IGF-2 gene hypomethylation frequency (46.3%) was significantly higher than that of patients without lymph node metastasis (17.2%), suggesting that abnormal IGF-2 gene hypomethylation might serve as a valuable biomarker in transitional cell carcinoma diagnosis and a potential indicator of transitional cell carcinoma prognosis.