FSTL3 and choriocarcinoma: Of importance, several genes inhibited by ERBB2/ERBB3 [75] were downregulated in choriocarcinoma, among which ADAM19 (Disintegrin And Metalloproteinase Domain-Containing Protein 19), FN1 (fibronectin 1), and FSTL3 (Follistatin Like 3) are involved in cell–cell and cell–matrix interactions and may impact cell adhesion during chorio-carcinogenesis.