A method for enhancing cell survival and/or proliferation, the method comprising: (a) obtaining isolated cells comprising stem cells; and (b) contacting the isolated cells with an amount of a compound sufficient to improve survival and/or proliferation of the cells compared to the absence of the compound: wherein the compound is a compound of formula: wherein, L 2 is unsubstituted C 1 -C 6 alkylene; y is an integer from 0 to 1; z is an integer from 0 to 5; X is -N= or -CH=; R 1 is hydrogen or unsubstituted C 1 -C 6 alkyl; R 3 and R 4 are independently -C NR 14 R 15, -OR 18, or substituted or unsubstituted C 1 -C 6 alkyl, wherein if z is greater than 1, two R 3 moieties are optionally joined together to form a substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R 14 and R 15 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; and R 18 is hydrogen or unsubstituted C 1 -C 6 alkyl; or a racemate, diastereomer, tautomer, or a geometric isomer thereof, or a pharmaceutically acceptable salt thereof. (a) obtaining isolated cells comprising stem cells; and (b) contacting the isolated cells with an amount of a compound sufficient to improve survival and/or proliferation of the cells compared to the absence of the compound: wherein the compound is a compound of formula: wherein, L 2 is unsubstituted C 1 -C 6 alkylene; y is an integer from 0 to 1; z is an integer from 0 to 5; X is -N= or -CH=; R 1 is hydrogen or unsubstituted C 1 -C 6 alkyl; R 3 and R 4 are independently -C NR 14 R 15, -OR 18, or substituted or unsubstituted C 1 -C 6 alkyl, wherein if z is greater than 1, two R 3 moieties are optionally joined together to form a substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R 14 and R 15 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; and R 18 is hydrogen or unsubstituted C 1 -C 6 alkyl; or a racemate, diastereomer, tautomer, or a geometric isomer thereof, or a pharmaceutically acceptable salt thereof. wherein the compound is a compound of formula: wherein, L 2 is unsubstituted C 1 -C 6 alkylene; y is an integer from 0 to 1; z is an integer from 0 to 5; X is -N= or -CH=; R 1 is hydrogen or unsubstituted C 1 -C 6 alkyl; R 3 and R 4 are independently -C NR 14 R 15, -OR 18, or substituted or unsubstituted C 1 -C 6 alkyl, wherein if z is greater than 1, two R 3 moieties are optionally joined together to form a substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl; R 14 and R 15 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; and R 18 is hydrogen or unsubstituted C 1 -C 6 alkyl; or a racemate, diastereomer, tautomer, or a geometric isomer thereof, or a pharmaceutically acceptable salt thereof.