Protocol to generate human liver spheroids to study liver fibrosis induced by metabolic stress oleh Hyun Young Kim, Wonseok Lee, Xiao Liu, Haeum Jang, Sadatsugu Sakane, Raquel Carvalho-Gontijo Weber, Karin Diggle, Samuel A. Kerk, Christian M. Metallo, Tatiana Kisseleva, David A. Brenner