IL6 and cancer: Then, three in vivo mouse cancer models are established, and it is found that sequential PDT and PTT using Gd‐Ce6@SWNHs synergistically promotes systemic antitumor immune responses, where PTT stimulates dendritic cells (DCs) to secrete IL‐6 and TNF‐α, while PDT triggers upregulation of IFN‐γ and CD80.