FOXC2 and neoplasm: Since FoxP3 belongs to the Forkhead class of transcription factors that have members essential for both tumor and normal cell proliferation, our findings that QDD and MP4 bind to FoxP3 without showing any affinity for members of other Forkhead sub-classes such as FoxC2 and FoxD1 (SPR data now shown) support the specificity of these compounds.