Non-small cell lung cancers remain particularly refractory to current treatments. Thus, characterisation of new molecular targets whose expression during chemotherapy could stop tumour growth, is required. In order to identify these new targets, we applied RT-PCR differential display (RT-PCR-DD) to a non-small cell lung cancer line (NSCLC-N6) treated by an original chemical substance, VT1, capable of arresting the proliferation of NSCLC-N6 cells in G1 phase. This study enabled us to identify a novel RNA, which has a strong homology with a DNA clone (GenBank accession no.: AY166681). This RNA resides in 6p24-p25 within intron 2 of the HEF1 gene, has no apparent open reading frame and may consists of a single large exon. Antisense oligonucleotides indicated that this RNA is involved in the proliferation arrest induced with VT1 treatment in NSCLC-N6 cells. The structure of this novel RNA resembles that of the previous identified extremely long non-coding RNAs which seem to regulate gene expression. Thus, this novel B2 transcript may belong to this new expanding non-coding RNA family.