The present invention provides for boronic acid compounds, boronic esters, andcompositions thereof that can modulate apoptosis such as by inhibition ofproteasomeactivity. The compounds and compositions can be used in methods in inducingapoptosis and treating diseases such as cancer and other disorders associateddirectlyor indirectly with proteasome activity. The compounds of the invention arerepresented by general formula [I] below.(see formula I)