Propofol use may be superior to the use of inhalation agents for anesthesia during breast cancer surgery in terms of host defense immunity, but it did not alter the immune response (in terms of NK cells, CTLs, TNF-α, IL-6, and IL-10) or the apoptosis rate relative to sevoflurane in co-culture with a breast cancer cell line (93). Here, IL6 is linked to breast cancer.