ASZ1 and hepatocellular carcinoma: Use of two different yeast strains and domain swapping ruled out the possibility of experimental artifacts; (b) CoIP assays established that the interactions obtained in Y2H assay were strong enough to be reproduced in human hepatoma cells, in the presence of many other potential host interaction partners of the X, methyltransferase and the ORF3; (c) an in vitro pull down assay using partially purified recombinant proteins confirmed that the two interaction partners possess the required motif/signature sequence to associate with each other.