NRAS and neoplasm: Summary of results of the analysis of 27 recurrent NMTC tumours: DNA index, allelic state and chromosome copy number determined by FISH for chromosomes 6 (centromeric probe) and 7 (centromeric and EGFR locus specific probes) and mutation analysis of BRAF, EGFR, RAS (HRAS, KRAS and NRAS) genes and PIK3CA.