(center map)
(1) CDK4:cyclin D1*@cell - p27Kip1*@nucleus - p21Cip*@nucleus -t-> CDK4:cyclin D1*@nucleus
(2) p27Kip1*@nucleus+CDK4:cyclin D1*@nucleus -> CDK4:cyclin D1*:p27Kip1*@nucleus
(3) CDK4:cyclin D1*@nucleus - GSK3B@nucleus -> CDK4:cyclin D1*_Thr286_pho@nucleus
(4) p21Cip*@nucleus+CDK4:cyclin D1*@nucleus -> CDK4:cyclin D1*:p21Cip*@nucleus