The antitumor synergism between PAK4 silencing and immunogenic phototherapy of the engineered EVs in B16F10 tumor-bearing mice at different siRNA doses (L, 0.25 mg/kg; M, 0.5 mg/kg; H, 1 mg/kg). The average tumor growth curves (A) (n = 5), and the representative images (B) and weight (C) of the excised tumors after different treatments (n = 3). (D) Representative images of Hematoxylin and Eosin (H&E) staining of the excised tumors. The combination index (CI) for the combined treatment against tumor volume on different dates (E) and against tumor weight (F), as determined by using the CompuSyn method. PS, individual PAK4 silencing. IP, individual immunogenic phototherapy. PS + IP, the combined treatment between PAK4 silencing and immunogenic phototherapy. Fa, Fraction affected. Data in A and C are represented as mean ± SD. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001, ∗∗∗∗P < 0.0001.