Although the rate of infections is low, an increased risk of infections of all grades (HR 1.77, 95% CI 1.56-2.01, p < 0.00001), of grade 3 or higher (HR 1.77, 95% CI 1.28-2.43, p = 0.0005), and urinary tract infections (HR 1.59, 95% CI 1.19-2.12, p = 0.002) in patients treated with CDK4/6 inhibitors and closer follow-up for infections in these patients could prevent complications and early death (12). This evidence concerns the gene CDK4 and infection.