IFNL2 and cancer: To examine the expression levels of the endogenous IFN-λ, we compared the average expression of IFN-λ among all human genome genes and found that endogenous IFN-λ exhibited a relatively low level of expression in cancers (IFNL2, 10.503, IFNL3, 10.547 and all genes, 13.38, Fig. 2A).