Effects of MMP inhibitors (MMPI) on the invasiveness of carbon‐ion (C‐ion) irradiated PANC‐1 cells. (A) The expression of MMP2 protein in irradiated PANC‐1. (B) Invasion assay was carried out with addition of MMPI (GM6001, 25 μM). Data represent the mean ± SD of samples (n = 5). (C) Morphology of PANC‐1 after incubation for 5 h with GM6001, 25 μM. Bar, 10 μm. (D) Morphology of invaded PANC‐1 cells with or without pretreatment of MMPI (GM6001, 25 μM) are shown. Bar, 200 μm.