OAS1 and synovial sarcoma: Given that the risk-conferring A allele of rs10774671 is a splice acceptor site variant located at the junction between intron 5 and exon 6 and may switch the primary normal isoform to various alternatives, we assessed whether the altered allele A influences the expression of various isoforms of OAS1 in PBMCs and EBV-transformed B cell lines from patients with SS.