Moreover, mRNA expression of the spleen tyrosine kinase (Syk), which is directly responsible for ITAM-mediated signaling, was significantly increased in samples from BLV-infected cattle with persistent lymphocytosis induced by BLV, whereas it was decreased in samples from BLV-infected cattle with lymphoma, suggesting that the dynamics of Syk mRNA expression is closely related to the progression of BLV-induced disease [13]. This evidence concerns the gene SYK and lymphoma.