TSG101 and cancer: In the light of high incidence of increased TSG101 protein found together with its splice variant in NPC and breast tumor progression, we report herein that the expression of TSGΔ154-1054 prevents the polyubiquitination and degradation of TSG101 protein by binding competitively to Tal, and subsequently increased the oncogenicity of TSG101 in terms of enhancing cell proliferation and malignant tumor formation in nude mice.