Thus, by 120 hpf, the absence of circulation in Tnnt2 morphants causes liver deficiency comparable to that of cloche mutants lacking ECs (Figure 5G–L), indicating a vital role of blood circulation in formation of the sinusoidal network in the liver and liver growth in late development. The gene discussed is TNNT2; the disease is hyperinsulinemic hypoglycemia, familial, 4.