MTDH and cancer: Recently, a large body of research showed that radioresistance was related to inducing pathways (e.g., the PI3K/Akt pathway [13], NF-κB pathway [14], and Wnt pathway [15]), altering molecules (e.g., high mobility group protein box 1 (HMGB1) [16], metadherin (MTDH) [17], and microRNA [18]), mediating tumour anoxic effect [19], facilitating the tumour angiogenesis [20], cancer stem cells [21] and autophagy [22].