As described in acute CIPN, our study demonstrates the relationship between chronic neuropathy and being a carrier of specific polymorphisms (C1236T and C3435T) of the ABCB1 gene in patients treated with P. In addition, there are modifiable factors (obesity, smoking, or alcohol) that may influence its development. The gene discussed is ABCB1; the disease is obesity due to melanocortin 4 receptor deficiency.