No significant change was detected for CDKN2A/p16INK4a, CDKN2A/p14ARF,CDKN2B/p15INK4b, MTAP, IFNA and IFNB mRNAs in tumours with 9p21–23 LOH when compared to those with retained heterozygosity. This evidence concerns the gene MTAP and neoplasm.