The effect of OP on spheroid formation might be explained by (a) OP increases the expression of E-cadherin [44], an important role in spheroid compaction of breast carcinoma [46], hepatoma [47] and hepatocytes [48, 49] and/or (b) inhibition of Neu4 sialidase [38]. This evidence concerns the gene CDH1 and hepatocellular carcinoma.