To demonstrate the existence of the colon cancer risk subtypes, we applied the highest IDO1 peak (shown as a dotted blue line in Figure 4A) or the secondary IDO1 peak (the higher cut-off for IDO1expression, shown as a dotted red line in Figure 4A) to define the IDO1high and IDO1low populations, respectively, and then carried out stratification based on the median value of CD8A expression. The gene discussed is IDO1; the disease is malignant colon neoplasm.