Despite the association of NY-ESO-1 hypermethylation and consequential protein expression with chemosensitivity in patient samples, chemosensitivity of lung cancer cell lines to cisplatin treatment was unaffected by either 5-Aza-dC-induced promoter demethylation (and associated re-expression of NY-ESO-1) or siRNA-mediated knockdown of NY-ESO-1 in vitro. These results indicate that unknown extrinsic factors are present in patients (but absent in cell lines) that mediate chemosensitivity to cisplatin. The gene discussed is CTAG1B; the disease is lung cancer.