LAG3 and Mental deterioration: Concordantly, compared with PBS‐Lag3‐WT mice, PFF‐Lag3‐WT mice showed significant cognitive decline and emotional disorder, and although PFF‐Lag3‐ECs‐Cko mice still had inferior outcomes to PBS‐Lag3‐ECs‐Cko mice, they had superior outcomes to PFF‐Lag3‐WT mice (Figure 9A–I and Figure S10A–D, Supporting Information).