GDF2 and Immunodeficiency: GelMA/MS, BMSCs-BMP9, BMSCs-GelMA/MS-GFP, and BMSCs-GelMA/MS-BMP9 implants were created and delivered beneath the skin of mice with immunodeficiency by injection, using a 26G needle syringe, to evaluate the osteogenic potential of new composite biomaterial in vivo.