S100A9 and age-related macular degeneration: AMD sera with the greatest and most frequent IR and controls were used to conduct additional IP, 2D-GE and LC-MS/MS experiments, which identified five potential targets of autoreactivity (Table 1): two members of the heat shock protein 70 (HSP70) family, HSPA8 and HSPA9; another member of the HSP family, HSPB4, also known as alpha-crystallin A chain (CRYAA); Annexin A5 (ANXA5); and Protein S100-A9 (S100A9), also known as calgranulin B that, when complexed with S100A8, forms calprotectin.