Figure 3 illustrates the clinical appearance of keratitis caused by S. aureus after a full-thickness corneal graft. S. aureus has been associated with recurrent bacterial keratitis that causes scarring following each episode [43]. Although scarring is an undesirable complication of keratitis that can lead to vision loss, studies have demonstrated the beneficial role of the scarring process: the blockade of immune-mediated pathways responsible for scarring, such as CXCR2, result in overwhelming bacterial infection [44]. Here, CXCR2 is linked to bacterial infectious disease.