Among 14 samples of invasive carcinomas which had been stored in paraffin blocks for 7 years 1 (7.1%) turned out to be p16INK4a-negative, 1 (7.1%) stained poorly, 3 (21.4%) stained sporadically, 4 (28.4%)-focally and 5 (35.8%) expressed diffuse staining. Here, CDKN2A is linked to invasive carcinoma.