Table 3.

IC₅₀ values for PD153035 and 1–6 based on either autophosphorylation (AP) in EGFR tyrosine kinase from cell lysate or intact A431 cells, or by measuring cell growth inhibition in intact A431 cells.

	PD153035 [48]	1 [48]	2 [48]	3 [50]	4 [50]	5 [51]	6 [51]
Lysate EGFR TK AP	0.19 nM	75 nM	0.21 nM	0.04 nM	0.11 nM	ND	ND
A431 EGFR AP	14.6 nM	3230 nM	3.8 nM	6.7–20 nM	4–10 nM	3 ± 2 nM	8 ± 2.5 nM
A431 EGFR AP, 8 h *	ND	ND	ND	6.7–20 nM	10–50 nM	15 ± 7 nM	20 ± 5 nM
A431 cell growth	~2.9 μM	~10 μM	4.5 μM	ND	ND	ND	ND

* Concentration required to suppress kinase activity up to 8 h after the removal of the inhibitor, ND = not determined.