Both mice and humans store fat in distinct white fat depots within the abdomen/thoracic region (called VAT), under the skin (SAT), and in brown AT (BAT). Notable differences between mice and humans include prominent epididymal VAT in mice, absent in humans, more brown adipocytes in murine PVAT and potentially fewer B-1 cells in omental and PVAT in humans, although data on these depots in humans is limited. Pie charts represents relative abundance of B-1 (white) and B-2 cells (black) as percentages of total B cells at homeostatic condition in mice (left) and human (right).