Evaluating the expression level of IL-8, MCP-1 and IFN-γ genes in A549 cell line in response to infection with F15/LAM4/KZN(LAM sub-lineage), F11(LAM sub-lineage), F28 (S sub-lineage) and Beijing (L2-Beijing sub-lineage) genotypes showed that the higher level of upregulation in the both genes are induced in response to infection with M.tb LAM sub-lineages compared to the other sub-lineages[32],While they failed to detect the expression of IFN-γ in response to all strains. The gene discussed is IFNG; the disease is infection.