In this regard, it has been suggested by Witkiewicz, Knudsen, Dicker, and Knudsen (2011) that p16 expression in the absence of HPV‐DNA detection might be due to RB signaling pathway disturbance, which is not related to HPV infection, such as in the case of lymphoma and small cell lung cancer. Here, RB1 is linked to small cell lung carcinoma.