Sections of tissues including the brain, spinal cord, heart, lung, liver, kidney, spleen and testis from mice (+/+, +/- and -/-; n = 7, 7 and 7, respectively) were fixed in 10% buffered formalin and embedded in paraffin. Each paraffin section of thick 4 μm was stained with hematoxylin and eosin (HE).