  In formulating a generalized framework to study certain noncommutative
algebras naturally arising in representation theory, K. A. Brown asked if every
finitely generated Hopf algebra satisfying a polynomial identity was finite
over a normal commutative Hopf subalgebra. In this note we show that Radford's
biproduct, applied to the enveloping algebra of the Lie superalgebra pl(1,1),
provides a noetherian prime counterexample.
