The expression of PTGS2 which codes for a prostaglandin dehydrogenase synthase, was highly induced in cells upon infection with Mtb (32-fold at 4 hr; 60-fold at 24 hr) and the complement (28-fold at 4 hr; 55-fold at 24 hr), relative to the mutant (4.8-fold at 4 hr; 45-fold at 24 hr) (Fig. 5A, B,C). Here, PTGS2 is linked to infection.