SLIT2 and neoplasm: Furthermore, after treatment of 6 colorectal cancer cell lines with the demethylation agent 5-aza-2-deoxycytidine (5-aza-C), they demonstrated re-expression of SLIT2. In order to ascertain whether SLIT2 acted as a tumour suppressor, Dallol et al exposed colorectal cancer cell lines to ectopic SLIT2, finding that it could suppress colony formation.