SYK and glomerulonephritis: Taken together, these data suggest that treatment with a SYK inhibitor is effective in the reduction of antibody (when given early) and the reduction of the severity of glomerulonephritis (when given either early or late) in rodent models of antibody-mediated glomerulonephritis, and that these effects may be mediated via inhibition of SYK within both resident renal cells, such as mesangial cells, and within infiltrating leukocytes.