LAIR1 and cancer: The decreased serum levels of LAIR-1 in metastatic BC in our study patients’ cohort can be explained by the fact that LAIR-1 is not only expressed on lymphocytes, serving an inhibitory receptor function contributing to the tumor immunosuppressive microenvironment (TIME), but also LAIR-1 is overexpressed on cancer cells, playing a negative role in cancer progression.