For instance, generic imatinib in chronic myeloid leukemia has been associated with higher therapeutic failure rates [38,39] and increased toxicity [40,41,42,43], while generic abiraterone and aromatase inhibitors in prostate cancer showed reduced PSA suppression, a key biochemical marker of efficacy. This evidence concerns the gene CYP19A1 and chronic myelogenous leukemia, BCR-ABL1 positive.