We then studied the effects of NTP-GM-D17 and NTP-GM-L17 on a human leukaemia MOLT-4 cell line, which expresses a definite level of PD-1 mRNA with a relatively low level of methylated DNA in the PD-1 promoter region, compared with the other two cell lines examined (Jurkat and CEM cells) (Supplementary Fig. 1B, C). The gene discussed is PDCD1; the disease is leukemia.