Some embodiments include methods for treating, preventing, reversing, halting, or slowing the progression of cancer, comprising administering to a subject in need thereof an effective amount of one or more chemotherapeutic agents, or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition, wherein at least one of the chemotherapeutic agents is a cytotoxic granulocyte colony-stimulating factor receptor (GCFR) modulator. Methods are also disclosed for treating, preventing, reversing, halting, or slowing the progression of a hematopoietic disorder, comprising administered a therapeutically effective cytotoxic amount of a GCFR modulator to a subject in need thereof.