After 7-day co-culture of SG scaffolds and HF spheroids, gene expressions of SGs (Krt18, Acta2, and Foxc1) and HFs (Krt17, Alpl and Cdh3) in the SG scaffold were elevated in the presence of HF spheroids, indicating that the differentiation tendency of SGs and HFs in SG scaffolds was promoted by HF spheroids (Figure 2b, c). This evidence concerns the gene KRT17 and hydrops fetalis.