An in vitro method for preventing or reducing cell differentiation, the method comprising: (a) obtaining cells comprising stem cells or progenitor cells; and (b) contacting the cells with an amount of a compound having formula sufficient to prevent or reduce differentiation of the cells as compared to cells in the absence of the compound, wherein the compound of formula is as follows: wherein, L 2 is unsubstituted C 1 -C 6 alkylene; and y is an integer from 0 to 3; z is an integer from 0 to 5; X is -N=, -CH= or -CR 5 =; R 1 is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R 3 is OR 18, and R 18 is hydrogen or unsubstituted C 1 -C 10 alkyl; R 4 and R 5 are independently -CN, -S n R 6, -NR 7 R 8, -C R 9, -NR 10 -C R 11, -NR 12 -C -OR 13, -C NR 14 R 15, -NR 16 S 2 R 17, -OR 18, - S 2 N(R 19) 2, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, wherein n is an integer from 0 to 2; and R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13, R 14, R 15, R 16, R 17 and R 19 are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; or a racemate, diastereomer, tautomer, or a geometric isomer thereof, or a pharmaceutically acceptable salt thereof. (a) obtaining cells comprising stem cells or progenitor cells; and (b) contacting the cells with an amount of a compound having formula sufficient to prevent or reduce differentiation of the cells as compared to cells in the absence of the compound, wherein the compound of formula is as follows: wherein, L 2 is unsubstituted C 1 -C 6 alkylene; and y is an integer from 0 to 3; z is an integer from 0 to 5; X is -N=, -CH= or -CR 5 =; R 1 is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R 3 is OR 18, and R 18 is hydrogen or unsubstituted C 1 -C 10 alkyl; R 4 and R 5 are independently -CN, -S n R 6, -NR 7 R 8, -C R 9, -NR 10 -C R 11, -NR 12 -C -OR 13, -C NR 14 R 15, -NR 16 S 2 R 17, -OR 18, - S 2 N(R 19) 2, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, wherein n is an integer from 0 to 2; and R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13, R 14, R 15, R 16, R 17 and R 19 are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; L 2 is unsubstituted C 1 -C 6 alkylene; and y is an integer from 0 to 3; z is an integer from 0 to 5; X is -N=, -CH= or -CR 5 =; R 1 is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R 3 is OR 18, and R 18 is hydrogen or unsubstituted C 1 -C 10 alkyl; R 4 and R 5 are independently -CN, -S n R 6, -NR 7 R 8, -C R 9, -NR 10 -C R 11, -NR 12 -C -OR 13, -C NR 14 R 15, -NR 16 S 2 R 17, -OR 18, - S 2 N(R 19) 2, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, wherein n is an integer from 0 to 2; and R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13, R 14, R 15, R 16, R 17 and R 19 are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl;