TABLE 2

A direct comparison of liver microsomes, liver S9, suspended hepatocytes, and two advanced hepatocyte systems—HμREL coculture and spheroids—on the same set of 10 commercially available compounds comprising 15 major circulating metabolites

	Hepatocyte Spheroids	HμREL Cocultured Hepatocytes	Suspension Hepatocytes	Liver S9^a	Liver Microsomes^b
Major metabolites correctly predicted	9^c	10	8	8	5
First-generation metabolites predicted	6	7	6	7	5
Second-generation metabolites predicted	3	3	2	1	0

↵^aLiver S9 was incubated with cofactors NADPH, glutathione, and UDPGA.
↵^bLiver microsomes were incubated with cofactors NADPH and UDPGA.
↵^cThree metabolites were detected in only one of two donors in the spheroid experiments.