We show that every n-dimensional, κ-noncollapsed, noncompact, complete ancient solution to the Ricci flow with uniformly PIC for n = 4 or n ≥ 12 has weakly PIC 2 and bounded curvature. Combining this with the results in [12], we prove that any such solution is isometric to either a family of shrinking cylinders (or a quotient thereof) or the Bryant soliton. Also, we classify all complex 2-dimensional, κ-noncollapsed, complete ancient solutions to the Kähler Ricci flow with weakly PIC.