Western blotting was performed as previously (18 , 19 (link)) and visualized and quantified using a Fluor-S Multi-Imager with Multi-Analyst software (Bio-Rad, Hercules, CA, USA). We utilized a rabbit anti-Ctsk antibody previously generated in our lab (11 (link)) and a goat anti-rabbit IgG-HRP (7074S, Cell signaling, Danvers, MA, USA) for this Western analysis.