In the current study, one site (S428) on the CEP55 amino acid sequence was found to be significantly phosphorylated in HNSC and breast cancer, and another two sites, namely, S23 and S436, were also significantly phosphorylated in HNSC versus corresponding normal tissue, a feature that can be connected with the hyperactivity of CEP55 that finally led to tumor progression. The gene discussed is CEP55; the disease is neoplasm.