The plausibility of our association with the number of pregnancies is supported by a recent review on the biological mechanisms of oestrogen in head and neck cancer that highlighted an increased expression of oestrogen receptors (ERs) including nuclear ERs (ERα and ERβ) and membrane‐bound forms (ERα36, GPER1 and NaV1.2) in various head and neck squamous cell carcinomas (HNSCC) [52]. This evidence concerns the gene ESR2 and head and neck squamous cell carcinoma.