USP22 and cancer: IHC analysis shows USP22 nuclear immunostaining was undetectable in the vast majority of normal lung tissues (Fig. 1a), and scant, weak nuclear USP22 immunostaining was observed in a very small part of normal tissues (6/163, 163 cancer tissues had the paired normal tissues), and a moderate to strong nuclear immunostaining of USP22 were found NSCLC tissues.