S100A2 and neoplasm: However, six patients (15%) showed overexpression of S100A2 but not ΔNp63, and one out of 40 patients (2.5%) showed overexpression of ΔNp63 but not S100A2, indicating that other mechanisms in addition to ΔNp63 transcription are at least partly responsible for the high-level expression of S100A2 in tumour tissue.