Dual-luciferase assays showed that compared with SOMK, SOMKP transduction significantly increased NANOG promoter activities by 1.74-, 1.46-, and 1.25-fold during reprogramming of HF-MSCs into HF-iPSCs on days 7 (P < 0.01), 14 (P < 0.01), and 21 (P < 0.05), whereas knockdown of PBX1 significantly decreased NANOG promoter activities on days 7 (P < 0.001), 14 (P < 0.001), 21 (P < 0.01), and 28 (P < 0.05; Fig. 5g). This evidence concerns the gene PBX1 and hydrops fetalis.