Hamasaki et al. revealed an excellent kappa coefficient of 0.8 by correlating the homozygous deletion of the 9p21 locus (P16/CDKN2A) detected by the FISH technique in pleural cytological samples of mesothelioma, with the immunohistochemical cytoplasmic loss of MTAP. The gene discussed is MTAP; the disease is mesothelioma.