CTSS and liver disorder: We next moved to primary Kupffer cells (KCs), since LPS-mediated KC activation is a key mechanism in the pathogenesis of various liver diseases.1 In KCs, LPS exposure induced p65-NF-κB nuclear translocation accompanied by a prominent MCP1 and IL6 mRNA induction that was blunted after CTSB or CTSS inhibition (Figures 4a and b).