PRDM9 is recurrently mutated in head and neck squamous cell carcinoma (Stransky et al., 2011), and an excess of rare PRDM9 alleles has been reported in aneuploid and infant B-cell precursor acute lymphoblastic leukemia patients (Hussin et al., 2013). Here, PRDM9 is linked to head and neck squamous cell carcinoma.