While it has been reported that the protein kinase A (PKA)-dependent phosphorylation of the corresponding serine residue in rat PDZK1 is necessary for the ability of overexpressed PDZK1 to increase endogenous SR-BI protein levels in Fao hepatoma cells [33], we found no discernable impact of phosphodefective or phosphomimetic mutations at this site on the interaction or localization of these proteins, suggesting that phosphorylation at this site causes more subtle effects on SR-BI biology in human hepatocytes. This evidence concerns the gene SCARB1 and hepatocellular carcinoma.