Preclinical studies indicate that dandelion extracts and isolated constituents exert selective cytotoxic and pro-apoptotic effects against various hematological malignancies, including leukemia and lymphoma, via mechanisms such as ROS generation, mitochondrial apoptosis, cell-cycle arrest and inhibition of oncogenic signaling (e.g., PI3K/AKT, STAT3). Here, STAT3 is linked to leukemia.