Ionizing radiation induces protective autophagy in parotid gland fibroblast cells. A. Hs917.T cells were exposed to a range of radiation doses as indicated, with or without 3-MA (10 mM) co-treatment for 24 h, and clonogenic assay was performed. *, P < 0.05. B. Hs917.T cells were exposed to a range of radiation doses as indicated, with or without CQ (10 μM) co-treatment for 24 h, and clonogenic assay was performed. *, P < 0.05.