The N3-propargyl (N3P) and N3-sulfoxide imidazotetrazine analogues [Table 1] demonstrated activity in cell lines irrespective of MMR status; the growth of MMR-deficient CRC cell lines HCT 116 (lacking MLH1; Figure 2) and DLD 1 (MSH6-negative) cells was inhibited [Table 2]. The gene discussed is MRC1; the disease is colorectal carcinoma.