SQSTM1 and cancer: Autophagy-defective tumor cells preferentially accumulate SQSTM1, and higher expressions of SQSTM1 have been detected in several cancers including prostate [10], breast [11], kidney [12], liver [13], lung [14], breast [15], oral [16], colon [11], ovarian [17], head and neck [11] and gastric cancers [11].