CNTN2 and synovial sarcoma: Sumida et al. [107] later described similar findings with the positive expression of tax gene in labial salivary glands from Japanese patients with SS, and they reported that the nucleotide sequence of the pX region in labial salivary glands was completely identical to that of the MT-2 cell line, suggesting that the findings of these two studies [106,107] support the concept that at least tax gene might be involved in the pathogenesis of SS.