Table 1.

Model variables and initial values

Variable name	Description	Initial value	Half-life
(1) E2media	E2 concentration in the media	10 nM	–
(2) E2cell	E2 concentration in the cell	10 nM	–
(3) ER	Estrogen receptor α	1.97 nM	∼4-5h38
(4) E2ER	Estrogen bound estrogen receptor α	835.19 nM	∼3-4h38
(5) E2NSB	Estrogen bound non-specific binding	6697.83 nM	–
(6) ICIER	ICI 182,780 bound estrogen receptor	0 nM	<3-4h38
(7) rescyclinD1palbo	Variable induced by palbociclib increasing cyclinD1	0 nM	–
(8) cyclinD1	Protein cyclinD1	0.62 $\times$ 10−6nM	∼0.4h39
(9) cdk46	Protein Cdk4/6	3365.58	∼5h40
(10) cdk46palbo	Palbociclib bound Cdk4/6	0 nM	–
(11) cdk46abema	Abemaciclib bound Cdk4/6	0 nM	–
(12) cyclinD1cdk46	CyclinD1 bound Cdk4/6	33.83 nM	–
(13) cyclinD1cdk46p21	p21 bound cyclinD1:Cdk4/6	21.84 nM	–
(14) cyclinD1cdk46palbo	Palbociclib bound cyclinD1:Cdk4/6	0 nM	–
(15) cyclinD1cdk46abema	Abemaciclib bound cyclinD1:Cdk4/6	0 nM	–
(16) cyclinD1cdk46p21palbo	Palbociclib bound cyclinD1:Cdk46:p21	0 nM	–
(17) cyclinD1cdk46p21abema	Abemaciclib bound cyclinD1:Cdk46:p21	0 nM	–
(18) cMyc	Protein c-Myc	9.75 nM	∼0.3h41
(19) p21	Protein p21	0.0027 nM	∼0.3-1h42
(20) cyclinE	Protein cyclinE	0.16 nM	∼0.5h43
(21) cyclinEp21	p21 bound cyclinE	0.036 nM	–
(22) Rb	Retinoblastoma protein	53.01 nM	∼2-3h44
(23) pRb	Hypophosphorylated RB1 (RB1-p)	16.64 nM	∼2-3h44
(24) ppRb	Hyperphosphorylated RB1 (RB1-pp)	0.49 nM	>4h44
(25) respropalbo	Variable induced by palbociclib inhibiting proliferation	0 nM	–
(26) Nalive	Alive cell number	0.93a	–
(27) Ndead	Dead cell number	0.07a	–

Variable names are italicized.

^aThe values of Nalive and Ndead are assigned according to the alive and apoptotic percentage in Figure S5.