Interestingly, a number of genes that change their expression in immortalized cells, e.g. PI3K, MDM2, SMAD2/3 and STAT1 (Supplementary Figure S4), are implicated in the evasion of apoptosis and acquisition of insensitivity to growth-inhibiting signals, which are characteristic features of tumour cells. Here, SMAD2 is linked to neoplasm.