CDKN2A and neoplasm: Among 39 cases, 27 (69.23%) exhibited a homozygous deletion of the CDKN2A gene in more than 20% of tumour cells, 8 (20.51%) harboured a percentage of heterozygous deletion in over 50% of tumour cells, and 4 (10.26%) had no detectable CDKN2A copy number variation.