On the other hand, Shah and colleagues found that IL-1β release is inversely correlated with the virulence in mycobacterial species based on the detection of IL-1β levels in the culture supernatant following infection with Mycobacterium smegmatis, Mycobacterium fortuitum, M. kansasii, MTB H37Ra and MTB H37Rv. This evidence concerns the gene IL1B and infection.