KRAS and cancer: Contaminants included the cancer genes KRAS (2 samples, including one sample identified by manual review), STAG2 (35 samples), DDX58 (25 samples; DDX58 encodes RIG-I), and SNAP25 (9 samples), some of which can be traced to other projects from the same laboratory [17, 18] (Fig. 3A; Additional file 3: Table S2).