Given the task definition and input, reply with output. Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Context: To investigate whether the aberrant expression of microRNA (miR)-196a and miR-196b can be used as potential prognostic markers of human osteosarcoma.', "Quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis was performed to detect the expression levels of miR-196a and miR-196b in osteosarcoma tissues and patients' sera.", 'Expression levels of miR-196a and miR-196b in osteosarcoma tissues were both significantly higher than those in noncancerous bone tissues (both p<0.001), in line with which, the serum levels of the two miRNAs were also markedly upregulated in patients with osteosarcomas compared with healthy controls (both p<0.001). Then, the elevation of serum miR-196a and miR-196b levels both more frequently occurred in osteosarcoma patients with high tumor grade (p=0.008 and 0.01, respectively), positive metastasis (p=0.001 and 0.006, respectively) and recurrence (p=0.001 and 0.006, respectively). Moreover, high serum miR-196a, high serum miR-196b and conjoined expression of miR-196a/miR-196b were all independent prognostic factors for OS (overall survival) and DFS (disease-free survival) of osteosarcoma patients.
Answer: Our present data indicate the involvement of miR-196a and miR-196b upregulation in the pathogenesis of osteosarcoma. More importantly, the altered levels of circulating miR-196a and miR-196b might have great potential to serve as novel and non-invasive prognostic factors for this malignancy.
Does combined elevation of microRNA-196a and microRNA-196b in sera predict unfavorable prognosis in patients with osteosarcomas?