TLR4 and leprosy: Although in the study by Krutzik et al. the TLRs being activated and regulated in leprosy were reported to be TLR2 and TLR1, and the response through TLR4 was described as weak, however, TLR4 and TLR9 have also been implicated in recognizing proteins from other mycobacteria such as Mycobacterium tuberculosis (Means et al., 1999, 2001; Jung et al., 2006), M. paratuberculosis (Byun et al., 2012) and M. bovis bacillus Calmette-Guerin (BCG; Fremond et al., 2003).