TNF and pneumonia: As well as by cholesterol levels, SQS activity can be regulated by administering lipopolysaccharide (LPS), mimicking infection by gram-negative bacteria, which results in pneumonia, bloodstream infections, etc. [35] Similarly, SQS can also be regulated by the proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) [36].