A folate analogue named LY3458991,18 (Fig. S1) impeded tumor growth in a mice xenograft model of colorectal cancer through intraperitoneal injection1, however, demonstrated greater inhibitory activity against MTHFD1 (IC50: 96 nM) over MTHFD2 (IC50: 663 nM), thus presenting potential safety risk. This evidence concerns the gene MTHFD2 and neoplasm.