Fig. 5.

CCNE1 and CCNE1/RB1 ratio as markers of de novo resistance to palbociclib. a Bar plot of the absolute value of Pearson’s correlation coefficient of IC50 values versus expression of RB1, CCNE1, and CCNE1/RB1 by considering both IC50 values and expression data for 827 cell lines of different tumors from Iorio et al., 2016²⁰ (light gray); IC50 values and expression data for 31 BC cell lines from Finn et al., 2009¹⁹ and Iorio et al., 2016²⁰, respectively (dark gray). b Histogram of the absolute value of Pearson’s correlation coefficient of CCNE1/RB1 versus IC50 values for 265 compounds tested in the cancer cell line dataset of Iorio et al.²⁰ Palbociclib is the compound showing the most significant association with CCNE1/RB1. ***P < 0.001; by correlation test. c Bar plot of the absolute value of Pearson’s correlation coefficient of IC50 values versus expression of Rb, Cyclin E1, and Cyclin E1/Rb by considering IC50 values and protein expression data for 237 cell lines of different tumors from Iorio et al.,²⁰ and MCLP²¹, respectively (light gray); IC50 values and expression data for 31 BC cell lines from Finn et al.¹⁹, and MCLP²¹, respectively (dark gray)