PDCD1 and renal carcinoma: Xiong et al. reported that RRM2 could regulate the sensitivity of renal cancer to sunitinib and PD-1 blockade via the stabilization of ANXA1 and the activation of the AKT pathway, and the effectiveness of the PD-1 blockade was improved by the deletion of RRM2 (Xiong et al., 2021b).