SULF2 and lung adenocarcinoma: Recent studies suggested that the methylation of the heparan sulfate 6-O-endosulfatase (SULF2) promoter is associated with better survival of lung adenocarcinoma patients, and silencing SULF2 through methylation could increase sensitivity to topoisomerase-1 inhibitors such as camptothecin (CPT) chemotherapy [3].