LAG3 and renal cell carcinoma: When segmenting patients by the presence or absence of brain metastases at the time of initial diagnosis of metastatic RCC, i.e., de novo brain metastasis, the differential expression of LAG3 between primary tumors and metastases was only preserved in those with de novo brain metastases and not in patients who developed brain metastases later in the course of their illness (Figure 3E).