A compound represented by Formula I or a pharmaceutically acceptable salt or ester thereof: wherein is selected from the groups below, is is R 1 and R 2 are each independently selected from the group consisting of: 1) Hydrogen; 2) Optionally substituted -C 1 -C 8 alkyl; 3) Optionally substituted -C 2 -C 8 alkenyl; 4) Optionally substituted -C 2 -C 8 alkynyl; 5) Optionally substituted -C 3 -C 8 cycloalkyl; 6) Optionally substituted aryl; 7) Optionally substituted arylalkyl; 8) Optionally substituted 3- to 8- membered heterocycloalkyl; 9) Optionally substituted heteroaryl; and 10) Optionally substituted heteroarylalkyl; X is N or C-R 3; R 3 is selected from the group consisting of: 1) Hydrogen; 2) Halogen; 3) Optionally substituted -C 1 -C 8 alkyl; and 4) Optionally substituted -C 1 -C 8 alkoxyl; R 4 is selected from the group consisting of: 1) Hydrogen; 2) Halogen; 3) Optionally substituted -C 1 -C 8 alkyl; 4) Optionally substituted -C 2 -C 8 alkenyl; 5) Optionally substituted -C 2 -C 8 alkynyl; 6) Optionally substituted -C 3 -C 8 cycloalkyl; 7) Optionally substituted aryl; 8) Optionally substituted arylalkyl; 9) Optionally substituted 3- to 8- membered heterocycloalkyl; 10) Optionally substituted heteroaryl; 11) Optionally substituted heteroarylalkyl; and 12) -N(R 5)(R 6); wherein R 5 and R 6 are independently selected from the group consisting of hydrogen, -C 1 -C 8 alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, wherein the -C 1 -C 8 alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl is substituted with 0-3 substituents independently selected from halo, alkyl, alkylamino, dialkylamino, alkylC NH-, arylC NH-, heteroarylC NH-, -CN, alkoxy, -CF 3, aryl, and heteroaryl; alternatively, R 5 and R 6 are taken together with the nitrogen atom to which they are attached to form an optionally substituted heterocyclic; and wherein the term "substituted" refers to the independent replacement of one or more of the hydrogen atoms thereon with substituents independently selected from halo; C 1 -C 4 -alkyl; halo-C 1 -C 4 -alkyl; C 2 -C 4 -alkenyl; halo-C 2 -C 4 -alkenyl; C 3 -C 6 -cycloalkyl; C 1 -C 4 -alkoxy; halo-C 1 -C 4 -alkoxy; -CN; -OH; NH 2; C 1 -C 4 -alkylamino; di(C 1 -C 4 -alkyl)amino; and NO 2. is selected from the groups below, is is R 1 and R 2 are each independently selected from the group consisting of: 1) Hydrogen; 2) Optionally substituted -C 1 -C 8 alkyl; 3) Optionally substituted -C 2 -C 8 alkenyl; 4) Optionally substituted -C 2 -C 8 alkynyl; 5) Optionally substituted -C 3 -C 8 cycloalkyl; 6) Optionally substituted aryl; 7) Optionally substituted arylalkyl; 8) Optionally substituted 3- to 8- membered heterocycloalkyl; 9) Optionally substituted heteroaryl; and 10) Optionally substituted heteroarylalkyl; 1) Hydrogen; 2) Optionally substituted -C 1 -C 8 alkyl; 3) Optionally substituted -C 2 -C 8 alkenyl; 4) Optionally substituted -C 2 -C 8 alkynyl; 5) Optionally substituted -C 3 -C 8 cycloalkyl; 6) Optionally substituted aryl; 7) Optionally substituted arylalkyl; 8) Optionally substituted 3- to 8- membered heterocycloalkyl; 9) Optionally substituted heteroaryl; and 10) Optionally substituted heteroarylalkyl; X is N or C-R 3; R 3 is selected from the group consisting of: 1) Hydrogen; 2) Halogen; 3) Optionally substituted -C 1 -C 8 alkyl; and 4) Optionally substituted -C 1 -C 8 alkoxyl; 1) Hydrogen; 2) Halogen; 3) Optionally substituted -C 1 -C 8 alkyl; and 4) Optionally substituted -C 1 -C 8 alkoxyl; R 4 is selected from the group consisting of: 1) Hydrogen; 2) Halogen; 3) Optionally substituted -C 1 -C 8 alkyl; 4) Optionally substituted -C 2 -C 8 alkenyl; 5) Optionally substituted -C 2 -C 8 alkynyl; 6) Optionally substituted -C 3 -C 8 cycloalkyl; 7) Optionally substituted aryl; 8) Optionally substituted arylalkyl; 9) Optionally substituted 3- to 8- membered heterocycloalkyl; 10) Optionally substituted heteroaryl; 11) Optionally substituted heteroarylalkyl; and 12) -N(R 5)(R 6); 1) Hydrogen; 2) Halogen; 3) Optionally substituted -C 1 -C 8 alkyl; 4) Optionally substituted -C 2 -C 8 alkenyl; 5) Optionally substituted -C 2 -C 8 alkynyl; 6) Optionally substituted -C 3 -C 8 cycloalkyl; 7) Optionally substituted aryl; 8) Optionally substituted arylalkyl; 9) Optionally substituted 3- to 8- membered heterocycloalkyl; 10) Optionally substituted heteroaryl; 11) Optionally substituted heteroarylalkyl; and 12) -N(R 5)(R 6); wherein R 5 and R 6 are independently selected from the group consisting of hydrogen, -C 1 -C 8 alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, wherein the -C 1 -C 8 alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl is substituted with 0-3 substituents independently selected from halo, alkyl, alkylamino, dialkylamino, alkylC NH-, arylC NH-, heteroarylC NH-, -CN, alkoxy, -CF 3, aryl, and heteroaryl; alternatively, R 5 and R 6 are taken together with the nitrogen atom to which they are attached to form an optionally substituted heterocyclic; and wherein the term "substituted" refers to the independent replacement of one or more of the hydrogen atoms thereon with substituents independently selected from halo; C 1 -C 4 -alkyl; halo-C 1 -C 4 -alkyl; C 2 -C 4 -alkenyl; halo-C 2 -C 4 -alkenyl; C 3 -C 6 -cycloalkyl; C 1 -C 4 -alkoxy; halo-C 1 -C 4 -alkoxy; -CN; -OH; NH 2; C 1 -C 4 -alkylamino; di(C 1 -C 4 -alkyl)amino; and NO 2.