A team of Brazilian researchers have succesfully bioprinted tiny organoids that perform all of the human liver’s functions, Brazilian news service Agência FAPESP reports — functions including building proteins, storing vitamins and secreting bile.

The researchers had to cultivate and reprogram human stem cells, and then 3D print them in layers to form tissue.

While the “mini-livers” perform the functions of a liver, they’re unfortunately still a far cry from an actual full-scale liver.