IRAK1 and leukemia: Thus, in different subtypes of SCLL, IRAK1 promotes accumulation of MDSCs with a consequential suppression of cytotoxic T-cells, allowing development of SCLL, supporting the hypothesis that IRAK1 expressing SCLL cells escape immune recognition by inducing MDSCs, which suppress cytotoxic T-cell function, whereas loss of IRAK1 fails to suppress T-cell mediated leukemia cell clearance.