Pictured is a frozen section slide stained by hematoxylin and eosin (H&E). The cover shows a poorly differentiated non-small cell carcinoma comprising of large pleomorphic tumor cells with high nuclear cytoplasmic ratio, hyperchromatic nuclei, prominent nucleoli and amphophilic to eosinophilic cytoplasm. A prominent mononuclear cell inflammatory response is also noted. This is one of the tumor specimens used by Sobol and colleagues (beginning on page 117, in this issue). In their study, the authors show that a switch in splicing isoforms of the deubiquitinase OTUD6B plays an important role in growth and proliferation of non-small lung cancer cells.