CDK2 and hydrops fetalis: Given our observation that the 10 hub genes from the shared DEGs of HF and KF were strongly enriched in immune and inflammation pathway (Figure 3D), and considering that the signature genes CDK2 and CCND1 emerged as potential diagnostic biomarkers for both conditions via nomogram model, we performed immune cell infiltration analysis to delve deeper into the immune regulation of HF and KF.