TLR4 and Bruton-type agammaglobulinemia: Blood monocytes from XLA patients have impaired phagocytic functions [10] and TNF-α production upon TLR2 or 4 stimulation [11], however other studies report similar [12] or enhanced cytokine production upon stimulation of TLR4, 7 and 8 in XLA monocytes [13], [14].