High PD-L1 expression was found only in 4 cases of 29 lung cancer patients (13.8%) (Fig. 8C(b) and Fig. 8C(c)), and all the 4 patients with higher PD-L1 expression had higher USP24 expression (Fig. 8C(b) and Fig. 8C(c)). Here, USP24 is linked to lung cancer.