Image 1.

RNA in situ hybridization for TP63 in tissues from formalin-fixed, paraffin-embedded (FFPE) blocks stored for different lengths of time. A, FFPE block from less than 1 year of age showing strong signals for TP63 probe set in prostatic basal cells (arrows). B, Another FFPE block from less than 1e year of age showing similar strong basal cell signals. Note absence of luminal cell or stromal cell signals. C, FFPE block that is 5 years of age showing markedly reduced signals. D, FFPE block that is 8 years old also showing greatly diminished signals. (×100)