TREM2 deficiency does not slow mouse glioma progression. (A) A schematic illustration of establishing an immunocompetent glioma model using murine glioma GL261 cells. (B) To determine the expression of Trem2 in the GL261 cell line, CD11b⁺ cells were sorted from gliomas of both WT and Trem2^−/− mice, serving as positive and negative controls, respectively. (C) The mRNA levels of Trem2 in the contralateral and tumor hemispheres were quantified by qRT-PCR. (D, E) Bioluminescence imaging was used to track and monitor the same mice over a period of 21 days. The statistical analysis showed that brain tumor burden was relatively higher in Trem2^−/− mice compared to WT mice. (F) A larger tumor size was observed in Trem2^−/− mice compared to the WT mice 21 days after tumor inoculation, as indicated by the increased weight of tumor hemisphere. (G–I). The survival study using 26 WT (12 males and 14 females) and 23 Trem2^−/− (9 males and 14 females) mice showed Trem2 deficiency did not confer any survival benefit in glioma. The data were shown as mean ± SEM. The data were tested for normal distribution using Shapiro–Wilk test first. P-values were acquired using 2-tailed Student t tests or 2-way ANOVA if the data were normally distributed, or Mann–Whitney test if they were not. Survival curves were analyzed using log-rank test.