IL6 and breast cancer: Cryo-thermal therapy alone could reduce the proportion of MDSCs and promote the expression of MHC II and CD86 on MDSCs, but the NF-κB pathway in MDSCs was also enriched, resulting in a high level of IL-6 after treatment, which indicated that cryo-thermal therapy could not maximally reverse immunosuppression induced by MDSCs in 4T1 breast cancer model.