CXCL12 and age-related macular degeneration: CXCL12 also strongly induced ERK1/2 phosphorylation (from 7±3.4 to 203±8.7; n = 6), and this effect was totally inhibited by pre-treatment with AMD, PD98059 or WM (6±2.2, 16±3.2 and 24±5, respectively; n = 6).