“…The asymptotic stability of radially symmetric stationary solutions was also analyzed in [55,56]. For cases in the presence of inhibitor, Wang et al [44] obtained the existence of symmetric-breaking stationary solutions for µ n (even n > n * * ); also see a very recent paper [41] for the discussion on the existence of radially symmetric stationary solutions and the asymptotic behavior of radially symmetric transient solutions. Assuming β(t) = ∞, i.e., (1.8) holds, tumor models have been intensively studied; we refer the reader to [12-14, 16, 19, 23, 26, 27, 29-31, 43, 49, 50, 52, 53] and the reference therein.…”