Overnight coincubation of PS-341 (7nM) with FLCs (κ2 and λ2) inhibits renal epithelial cell production of MCP-1. HK-2 cells were incubated overnight in medium that contained PS-341 (7mM) and 2 different FLCs (κ2 and λ2). While PS-341 did not affect MCP-1 production by cells incubated in medium alone, FLC-induced MCP-1 production was partially inhibited. *P < .05 compared with sample containing the corresponding FLCs; n = 6 in each group