WNT4 and basal cell carcinoma: Genes downregulated in Pigl−/− mTSCs were associated with basal cell carcinoma, signaling pathways regulating pluripotency of stem cells, WNT signaling pathway genes such as Wnt3 and Wnt4 [20], and differentiation and MAPK signaling pathways, including essential genes involved in regulating placenta development such as Gcm1, Cited1, and Ascl2 [9] (Fig. S2J and Supplementary file 7).