HKDC1 and testicular germ cell tumor: Our discoveries indicated that HKDC1 mRNA expression exhibits a negative correlation with methylation levels at multiple sites across the majority of tumor types examined, particularly in adrenocortical carcinoma (ACC), breast carcinoma (BRCA), acute myeloid leukemia (LAML), mesothelioma (MESO), prostate adenocarcinoma (PRAD), testicular germ cell tumors (TGCT), and uveal melanoma (UVM).