A foamable or foamed article comprising a diene terpolymer, the diene terpolymer comprising (or consisting essentially of) from 0.01 wt % to 10.0 wt % diene derived units, and 1.0 wt % to 20 wt % of C4 to C10 α-olefin derived units based on the weight of the diene terpolymer, wherein the diene terpolymer: a) has a g′vis of less than 0.90; b) has an Mw within a range of from 100,000 g/mol to 500,000 g/mol; c) has an Mw/Mn within the range of from 3.5 to 12.0; and d) an Mz/Mn of greater than 7.0. Inventive articles comprise a blend of a relatively high density linear polyethylene and the diene terpolymer.