J22352, a PROTAC (proteolysis-targeting chimeras)-like and highly selective HDAC6 inhibitor with an IC50 value of 4.7 nM, enhances anticancer effects in glioblastoma by promoting HDAC6 degradation. It does so by inhibiting autophagy and stimulating the antitumor immune response, further restoring host antitumor activity through the reduction of PD-L1's immunosuppressive activity.