Among them, 4/6 were associated with pembrolizumab and manifested as AKI; 3/6 presented with concomitant tubular-interstitial injury; 2/6 presented with macroscopic hematuria, and our case is unique for its remarkable red cell casts; 2/6 presented with lower C3 serum level; 3/6 presented with skin rashes; 4/6 responded to ICIs discontinuation and initiation of glucocorticoids. Here, C3 is linked to acute kidney injury.