Patients carrying CYP3A4 defective variants had more severe neuropathy and higher probability of neuropathy‐induced paclitaxel treatment modifications; hence, CYP3A4 defective variants are a genetic marker associated with paclitaxel treatment modifications caused by neuropathy (Apellaniz‐Ruiz et al., 2015). Here, CYP3A4 is linked to neuropathy.