A compound of Formula I-0: or a pharmaceutically acceptable salt thereof, wherein: - - - - - - - - is a single bond or a double bond; R 1 is H, CH 3, CF 3, F, Cl, Br, or -OCF 3; R 2 is H, C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, or C 6-10 aryl, wherein each of the C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, or C 6-10 aryl is substituted by 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, and C 1-6 haloalkoxy; R 3 is NR 3a R 3b, wherein, R 3a is H, C 1-6 alkyl, C 1-6 haloalkyl, cycloalkylalkyl, C 3-7 cycloalkyl, arylalkyl, or C 6-10 aryl, wherein each of the C 1-6 alkyl, C 1-6 haloalkyl, cycloalkylalkyl, C 3-7 cycloalkyl, or C 6-10 aryl is substituted by 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, and C 1-6 haloalkoxy, and R 3b is H, C 1-6 alkyl, C 1-6 haloalkyl, cycloalkylalkyl, C 3-7 cycloalkyl, arylalkyl, or C 6-10 aryl, wherein each of the C 1-6 alkyl, C 1-6 haloalkyl, cycloalkylalkyl, C 3-7 cycloalkyl, arylalkyl, or C 6-10 aryl is substituted by 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, and C 1-6 haloalkoxy; or R 3a and R 3b together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group that is substituted with 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl, and heterocycloalkyl; and R 4 is H, C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, or C 6-10 aryl, wherein each of the C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, or C 6-10 aryl is substituted by 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, and C 1-6 haloalkoxy. - - - - - - - - is a single bond or a double bond; R 1 is H, CH 3, CF 3, F, Cl, Br, or -OCF 3; R 2 is H, C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, or C 6-10 aryl, wherein each of the C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, or C 6-10 aryl is substituted by 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, and C 1-6 haloalkoxy; R 3 is NR 3a R 3b, wherein, R 3a is H, C 1-6 alkyl, C 1-6 haloalkyl, cycloalkylalkyl, C 3-7 cycloalkyl, arylalkyl, or C 6-10 aryl, wherein each of the C 1-6 alkyl, C 1-6 haloalkyl, cycloalkylalkyl, C 3-7 cycloalkyl, or C 6-10 aryl is substituted by 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, and C 1-6 haloalkoxy, and R 3b is H, C 1-6 alkyl, C 1-6 haloalkyl, cycloalkylalkyl, C 3-7 cycloalkyl, arylalkyl, or C 6-10 aryl, wherein each of the C 1-6 alkyl, C 1-6 haloalkyl, cycloalkylalkyl, C 3-7 cycloalkyl, arylalkyl, or C 6-10 aryl is substituted by 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, and C 1-6 haloalkoxy; or R 3a and R 3b together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group that is substituted with 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl, and heterocycloalkyl; and R 4 is H, C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, or C 6-10 aryl, wherein each of the C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, or C 6-10 aryl is substituted by 0, 1, 2, 3, 4, or 5 substituents each independently selected from OH, amino, halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, and C 1-6 haloalkoxy.