A compound miRNA (miRNA661 ) (Nr MI0003669 or ENSG00000207574) the sequence of the mature miRNA-661 being 51 - ugccugggucucuggccugcgcgu- 74 for use as a medicament in the in the treatment and/or the diagnosis of cancer, neuronal disease and infection.Linvention concerne un composé de miARN (miRNA661) (N° MI0003669 ou ENSG00000207574), la séquence de miRNA-661 mature étant 51- ugccugggucucuggccugcgcgu-74, quon utilise comme médicament dans le traitement et/ou le diagnostic dun cancer, dune maladie neuronale et dune infection.