The present invention provides boronic acid compounds, boronic esters, and compositions thereof that can modulate apoptosis such as by inhibition of proteasome activity. The compounds and compositions can be used in methods of inducing apoptosis and treating diseases such as cancer and other disorders associated directly or indirectly with proteasome activity.本發明提供可調節細胞凋亡之二羥基硼酸(boronic acid)化合物、二羥基硼酸酯及其組成物,例如經由抑制蛋白酶體活性。化合物及組成物可用於誘導細胞凋亡及治療例如癌症疾病及其他直接或間接與蛋白酶體活性有關失調之方法。