0 -> AP1 AP1 -> 0 0 -> pRB E2F + pRB -> pRBc1 pRBc1 -> E2F + pRB pRB -> pRBp pRBp -> pRB pRB -> 0 pRBp -> pRBpp pRBpp -> pRBp E2F + pRBp -> pRBc2 pRBc2 -> E2F + pRBp pRBp -> 0 pRBpp -> 0 0 -> E2F E2F -> E2Fp E2Fp -> E2F E2F -> 0 E2Fp -> 0 0 -> Cd 0 -> Cd Cd -> Mdi Mdi -> Cd Cd -> 0 Cd -> 0 Md -> Mdi Mdi -> Md Md + p27 -> Mdp27 Mdp27 -> Md + p27 0 -> Ce Ce -> Mei Mei -> Ce Ce -> 0 Ce -> 0 Me -> Mei Mei -> Me Me + p27 -> Mep27 Mep27 -> Me + p27 0 -> Skp2 Skp2 -> 0 Skp2 -> 0 0 -> Pei Pe -> Pei Pei -> Pe Pei -> 0 Pe -> 0 0 -> Ca Ca -> Mai Mai -> Ca Ca -> 0 Ca -> 0 Ma -> Mai Mai -> Ma Ma + p27 -> Map27 Map27 -> Ma + p27 0 -> p27 0 -> p27 Mb + p27 -> Mbp27 Mbp27 -> Mb + p27 p27 -> p27p p27p -> p27 p27 -> 0 p27p -> 0 p27p -> 0 Cdh1a -> Cdh1i Cdh1i -> Cdh1a Cdh1i -> 0 Cdh1a -> 0 0 -> Cdh1a Pa -> Pai Pai -> Pa Pai -> 0 0 -> Pai Pa -> 0 0 -> Cb Cb -> Mbi Mbi -> Cb Cb -> 0 Cb -> 0 Cb -> 0 Mb -> Mbi Mbi -> Mb 0 -> Cdc20i Cdc20i -> Cdc20a Cdc20a -> Cdc20i Cdc20i -> 0 Cdc20a -> 0 0 -> Pbi Pb -> Pbi Pbi -> Pb Pbi -> 0 Pb -> 0 0 -> Wee1 0 -> Wee1 Wee1 -> Wee1p Wee1p -> Wee1 Wee1 -> 0 Wee1p -> 0 0 -> Cdc45 Cdc45 -> 0 Cdc45 -> Pol Pol -> Cdc45 0 -> Primer Primer -> 0 Primer -> ATR ATR -> Primer 0 -> Chk1 Chk1 -> 0