Effects of other proteases on carbon‐ion (C‐ion) irradiated PANC‐1 invasion at the dose of 2 Gy. (A) Invasion assay was carried out with the addition of protease inhibitors, aprotinin (Ap; 0.4 μM), bestatin (Be; 25 μM), E‐64 (E64; 7.5 μM), leupeptin (Leu; 10 μM) and pepstatin A (Pep; 5 μM). Data are represented as mean ± SD of samples (n = 6). *P < 0.05 versus control. (B) Invaded cells of irradiated PANC‐1 with or without pretreatment of aprotinin or pepstatin A are shown. Bar, 200 μm. No_IR, no irradiation.