MyD88 is dispensable for MDS/AML LSPCs. (A) Immunoblots for MyD88 and the activation of downstream pathways (phospho-p38, phospho-JNK, phospho-IKK, and phospho- extracellular signal-regulated kinase) in WT and MYD88^KO THP1 cells upon a 30-minute treatment with IL-1β (10 ng/µL) or the TLR1/2 ligand PAM3CSK4 (1 µg/mL) as compared with DMSO. (B) Immunoblots for IRAK4 and MyD88 in WT and MYD88^KO THP1 and MDSL cells transduced with nontargeting shControl or shIRAK4. (C) Colony formation of WT and MYD88^KO THP1 and MDSL cells transduced with nontargeting shControl or shIRAK4. (D) Representative colony images of WT and MyD88^KO MDSL cells transduced with nontargeting shControl or shIRAK4 (original magnification ×40). Significance was determined with a Student t test (∗P < .05). Error bars represent the standard deviation. DMSO, dimethyl sulfoxide.