CYP2C19 and breast cancer: In the GSE68086 dataset (the largest dataset in terms of the sample size—blood platelets from HC vs. blood platelets from BC patients), there was a decrease in the expression of genes AKR1B1, ALOX12B, ALOX15B, cytochromes CYP2C19, CYP4A11, CYP4F2, epoxide hydrolase EPHX4 and FAAH.