Furthermore, knockdown of CBX3 by infection with shRNAs or treatment with CSE or nicotine had no effect on the liver and renal function of nude mice according to serum analysis of aminoleucine transferase (ALT), aspartate transaminase (AST), creatinine (CRE), or blood urea nitrogen (BUN) in each group of nude mice (Supplementary Fig. 3g–j). The gene discussed is CBX3; the disease is infection.