The microRNA boost in the tumour was associated with the overexpression of genes involved in microRNA biogenesis such as Drosha, Xpo5, Dicer, and Ago2. Ribonuclease activity of RNase A was demonstrated to play crucial role both in antitumour/antimetastatic activity and the influence on the expression of microRNA and the microRNA processing genes. This evidence concerns the gene RNASE1 and neoplasm.