HAND1 and systemic lupus erythematosus: Moreover, embryo bodies derived from hiPSCs‐SLE were able to differentiate spontaneously towards the three germ layers as shown by RT‐qPCR for GATA4 (endoderm), HAND1 (mesoderm) and PAX6 (ectoderm), and by immunofluorescence for Otx2 (ectoderm), Sox17 (endoderm) and Brachyury (mesoderm) (Figure 1G‐I).