Iwahasi et al. took the serum of pregnant women with early-onset preeclampsia and normal pregnant women and detected PAPP-A in serum; using median comparison, they found that pregnant women with early-onset preeclampsia were lower than normal pregnant women (0.80 MoMs vs. 1.05 MoMs, P = 0.005), combined with RBP4, predicting a 34% increase in DR in early-onset preeclampsia, and PAPP-A can be used as a useful indicator for predicting early-onset and severe preeclampsia [11]. The gene discussed is RBP4; the disease is preeclampsia.