A combination for use in a method for treating cancer in a subject, the combination comprising: an effective amount of a T-cell checkpoint inhibitor which is an anti-PD-L1 antibody or an anti-PD-1 antibody and which prevents the T cell's PD-1 from binding to the PD-L1 presented on the cancer cell, and an effective amount of a heterobifunctional inhibitor chosen from compounds of Formula: and pharmaceutically acceptable salts thereof, wherein: R 1 is chosen from H, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups; R 2 is chosen from -OH, -NH 2, -OC(=O)Y 1, -NHC(=O)Y 1, and -NHC(=O)NHY 1 groups, wherein Y 1 is chosen from C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, C 2-8 haloalkynyl, C 6-18 aryl, and C 1-13 heteroaryl groups; R 3 is chosen from -CN, -CH 2 CN, and -C(=O)Y 2 groups, wherein Y 2 is chosen from C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, -OZ 1, -NHOH, -NHOCH 3, -NHCN, and-NZ 1 Z 2 groups, wherein Z 1 and Z 2, which may be identical or different, are independently chosen from H, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups, wherein Z 1 and Z 2 may together form a ring; R 4 is chosen from C 3-8 cycloalkyl groups; R 5 is independently chosen from H, halo, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups; n is chosen from integers ranging from 1 to 4; and Linker is chosen from linker groups. an effective amount of a T-cell checkpoint inhibitor which is an anti-PD-L1 antibody or an anti-PD-1 antibody and which prevents the T cell's PD-1 from binding to the PD-L1 presented on the cancer cell, and an effective amount of a heterobifunctional inhibitor chosen from compounds of Formula: and pharmaceutically acceptable salts thereof, wherein: R 1 is chosen from H, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups; R 2 is chosen from -OH, -NH 2, -OC(=O)Y 1, -NHC(=O)Y 1, and -NHC(=O)NHY 1 groups, wherein Y 1 is chosen from C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, C 2-8 haloalkynyl, C 6-18 aryl, and C 1-13 heteroaryl groups; R 3 is chosen from -CN, -CH 2 CN, and -C(=O)Y 2 groups, wherein Y 2 is chosen from C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, -OZ 1, -NHOH, -NHOCH 3, -NHCN, and-NZ 1 Z 2 groups, wherein Z 1 and Z 2, which may be identical or different, are independently chosen from H, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups, wherein Z 1 and Z 2 may together form a ring; R 4 is chosen from C 3-8 cycloalkyl groups; R 5 is independently chosen from H, halo, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups; n is chosen from integers ranging from 1 to 4; and Linker is chosen from linker groups. R 1 is chosen from H, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups; R 2 is chosen from -OH, -NH 2, -OC(=O)Y 1, -NHC(=O)Y 1, and -NHC(=O)NHY 1 groups, wherein Y 1 is chosen from C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, C 2-8 haloalkynyl, C 6-18 aryl, and C 1-13 heteroaryl groups; R 3 is chosen from -CN, -CH 2 CN, and -C(=O)Y 2 groups, wherein Y 2 is chosen from C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, -OZ 1, -NHOH, -NHOCH 3, -NHCN, and-NZ 1 Z 2 groups, wherein Z 1 and Z 2, which may be identical or different, are independently chosen from H, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups, wherein Z 1 and Z 2 may together form a ring; R 4 is chosen from C 3-8 cycloalkyl groups; R 5 is independently chosen from H, halo, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 haloalkyl, C 2-8 haloalkenyl, and C 2-8 haloalkynyl groups; n is chosen from integers ranging from 1 to 4; and Linker is chosen from linker groups.