1. β,β-Dimethylacrylshikonin (Dimethylacrylshikonin) is a promising agent for developing an improved strategy for radiotherapy against tumors. (a) Injection of Dimethylacrylshikonin combined with IR treatment significantly suppressed tumor growth of the HCT-116 xenograft. (b) Dimethylacrylshikonin significantly suppressed the growth of H(22) transplantable hepatoma, and induced the activation of caspase-3 . (c) Dimethylacrylshikonin inhibited growth of gastric cancer SGC-791 cells by inducing ERK signaling pathway. 2. Dimethylacrylshikonin inhibits the proliferation of MCF-7 cells in vitro by inducing apoptosis through the downregulation of Bcl-2, upregulation of Bax and partial inactivation of the NF-κB pathway.