Tamoxifen treatment induces deletion of MyD88 in YFP⁺ cells in cKO but not cHet mice. (A) cHet and cKO mice were treated with tamoxifen or left untreated, and YFP expression in the indicated splenocyte populations was determined 5 days later. (B) YFP⁺ and YFP⁻ splenocytes were FACS purified from tamoxifen-treated or untreated cHet and cKO mice, and MyD88 expression was determined by Western blot. (C) YFP⁺ and YFP⁻ CD4 and CD8 T cells were FACS purified from treated or untreated cKO mice, and MyD88 expression was determined by Western blot.