HTT and Huntington disease: To summarize their detailed findings, mHtt, TGM2, and CaM co-immunoprecipitate and also colocalize to disease-specific inclusions in the nuclei of HD cortical neurons; TGM2 selectively cross-links mHtt with expanded poly Q over normal Htt; and, mHtt with expanded poly Q binds CaM with selective affinity over normal Htt [139,149].