All reagents were purchased from Sigma (St. Louis, MO) unless noted otherwise. Anti-MUC1 mouse monoclonal antibody (GP1.4, Cat. # MA5–13168), Alexa Fluor 488-conjugated rabbit anti-mouse or goat anti-rabbit IgG, and Alexa Fluor 594-conjugated rabbit anti-mouse or goat anti-rabbit IgG were from Thermo Fisher Scientific (Waltham, MA). Polyclonal rabbit anti-mouse MUC1 antibody was from Abcam (Cat. # ab15481, Cambridge, MA). Horseradish peroxidase (HRP)-conjugated goat anti-mouse and goat anti-rabbit IgG antibodies were from Jackson ImmunoResearch Laboratories, Inc (West Grove, PA). The pCI-MUC1 expression plasmid and pCI-neo empty vector were a generous gift from Dr. Sandra J. Gendler (Mayo Clinic, Scottsdale, AZ). MUC1 smart pool siRNA and non-targeting control siRNA were purchased from Dharmacon (Lafayette, CO). Rabbit monoclonal anti-total ERK1/2, rabbit monoclonal anti-phospho-ERK1/2, and HRP-conjugated mouse monoclonal anti-beta actin antibodies were purchased from Cell Signaling (Danvers, MA). Polyclonal mouse anti-major surface glycoprotein (Msg) of Pneumocystis murina (P. murina) was generated as previously described (Bishop, Helman, & Kovacs, 2012 (link)). Human IL-6 and IL-8 ELISA kits were from R&D (Minneapolis, MN).