CYP1A1 and gastric cancer: Of the 30 upregulated genes by C. concisus, four genes were reported to be associated with gastric cancer including HSD17B8_2, TRIM27_2, TC2N_1, and CYP1A1. However, three of these genes had an underscore following their gene names, showing that they are on alternate reference locus (Bruford et al., 2020).