IL1R1 and neoplasm: Of note, using the aggressive PyMT mouse model of invasive breast carcinoma inter-crossed with the Il-1r KO background, Dagenais and colleagues observed an increase in tumor burden and aggressiveness, while no effect on the composition of the tumor immune microenvironment was noted, minimizing the role of the IL-1R pathway as a main modulator of breast cancer progression through the modulation of the immune composition (60).