Based on these observations, most of the cells could therefore be classified as anti-inflammatory M2 macrophages.28 In support of this hypothesis and using quantitative real-time polymerase chain reaction for representative M1 (CXCL11) and M2 (CCL22) transcripts, Cao et al.29 demonstrated high M2-chemokine transcripts and a low M1-to-M2 chemokine transcript ratio in aging non-AMD eyes. Here, CCL22 is linked to age-related macular degeneration.