HOTAIR can play a role in mediating molecular scaffolds, promoting the localisation of polycomb repressive complex 2 and the lysine-specific demethylase 1/CoREST/REST complex to the chromatin; this can then affect chromatin histone H3K27 trimethylation and H3K4me2 demethylation, resulting in the regulation of tumour-related gene expression2. The gene discussed is RCOR1; the disease is neoplasm.