The up-regulation of the IL-13 receptor, Il13ra1, in combination with the up-regulation of the IL-13 inducible Ccl24 and Pparγ genes (Table 2) by 15 min post H37Rv-infection suggests that an anti-inflammatory transcriptional response was initiated by IL-13 signaling during the initial phase of M. tuberculosis H37Rv infection. This evidence concerns the gene PPARG and infection.