DNA methylation status of CpG and non-CpG moieties in the 5′-flanking regions of the IL-1β and IL-6 genes has been studied by bisulphite treatment of genomic DNA purified from human neuroblastoma SK-N-BE cells, cultured for 24 h in control or 0.5 mM ALA supplemented medium. Here, IL1B is linked to neuroblastoma.