Incubation of the cells with individual PFAS and PFAS mixtures resulted in triglyceride accumulation, and in a consistent dysregulation of marker genes for steatosis, of PPARα target genes and of additional genes involved in lipid and cholesterol metabolism, e.g., CYP7A1. Regarding PPARα activation, synergistic effects were observed for the selected exposure-relevant PFAS mixtures being composed of PFOS, PFOS, PFNA and PFHxS. The gene discussed is CYP7A1; the disease is steatosis.