Conversely, compared with the HF + Exos + DMSO group, the expression of INSR, IRS-1, IRS-2, PI3K, p-AKT, Ras, and p-Erk1/2 decreased significantly in the hippocampus of mice in the HF + Exos + GW4869 group (Fig. 6G, H). Here, MAPK3 is linked to hydrops fetalis.