For further correlate the methylation status of the hTREX84 promoter and exon 1 region and hTREX84 expression, we analyzed 15 cases of breast and ovarian cancer cell lines, 10 cases of breast and ovarian immortal cell lines, 6 cases of invasive breast ductal carcinoma, 13 cases of ovarian tumors, as well as their paired normal tissues by sodium bisulfite DNA sequencing. Here, THOC1 is linked to ovarian carcinoma.