Important advantages for development and clinical applications of anticancer agents that target Sp1, Sp3 and Sp4 include: (a) Sp protein expression in non-tumor tissue is relatively low; (b) in cancer cells, these compounds decrease Sp-regulated genes such as EGFR, VEGF, cMET and other tyrosine kinases that are themselves individual drug targets; and (c) these agents also decrease expression of drug resistance genes (survivin, MDR1) [14] and are ideal for drug combination therapies. This evidence concerns the gene SP3 and cancer.