IRAK1-IN-1 (compound B8) is an orally active IRAK1 inhibitor. IRAK1-IN-1 inhibits the release of IL-6 with the IC 50 values of 4.57 μM and 6.51 μM on mouse cells J774A. 1 and human cells THP-1, respectively. IRAK1-IN-1 alleviats LPS -induced acute lung injury (ALI) and DSS-induced colitis in mice.