(center map)
(1) p53*@nucleus - CHEK2_Thr68_pho@nucleus - ATR@nucleus - ATM_Ser 1981_pho:NBS1__pho@nucleus -> p53*_Ser15_pho@nucleus
(2) p53*_Ser15_pho@nucleus - CHEK1_S317_pho_S345_pho@nucleus - CHEK2_Thr68_pho@nucleus -> p53*_Ser15_pho_Ser20_pho@nucleus