IRAK4 and acute myeloid leukemia: 18 Subtypes 1 and 3 share a similar protein signature (Figure 2D), but differ in kinase enrichment (Figure 2E), in which only IRAK4 appears enriched in subtype 1, whereas multiple kinases, including AURKA, a known regulator of AML therapy response,23 are enriched in subtype 3.