Among them, mouse double minute-4 p53 binding homolog (MDM4) and contactin 2 (CNTN2) are amplified in a subset of malignant gliomas without TP53 mutation or MDM2 amplification (5), SMYD2 is amplified in esophageal squamous cell carcinoma (6), and KIF14 is amplified in breast cancer (7). Here, CNTN2 is linked to breast cancer.