(A) Proinsulin+ cells (arrows) in the liver (a–d), abdominal adipose tissue (e–h), and bone marrow (i–l) of STZ (a, e, and i), ob/ob (b, f, and j), and high-fat diet (HFD; c, g, and k) diabetic mice and nondiabetic mice (d, h, and l). In nondiabetic mice, proinsulin+ cells were not found in the liver (d), adipose tissue (h), or bone marrow (l). (Scale bars, 25 μm.) (B) Overlap images of GFP/proinsulin in the liver (a–d), adipose tissue (e–h), and bone marrow (i–l) from STZ-induced diabetic (a–c, e–g, and i–k) and nondiabetic (d, h, and l) MIP-GFP mice. GFP and proinsulin signals completely overlap (arrows). (Scale bars: 25 μm, a–d; 20 μm, e–h; 10 μm, i–l). From Ref. 21 (with permission).