Tissues were fixed in 10% neutral-buffered formalin. Five-micrometer sections on charged glass slides were cleared through Xylenes (Fisher #X3P) to 100% ethanol and rehydrated through a graded alcohol series to distilled water. Immunostaining was performed as previously described . A list of all antibodies used for immunohistochemical stains appears in Supplementary Table 2. Stains were developed using ABC (Vector Labs #PK-6101) and Nova Red (Vector Labs #SK-4800) kits according to manufacturer's instructions.