EPC at the tissue level, measured by EPCt, in 47 mouse tissues. Comparisons of EPCt between glandular/endocrine tissues (with and without gonadal tissues) vs. nonglandular/nonendocrine tissues or between neuronal tissues vs. nonneuronal tissues are shown (P values are from the Mann–Whitney U test). The values of the upper quartile, median, and lower quartile are indicated in each box, whereas the bars outside the box indicate semiquartile ranges. org., organ.