For patients with acute myeloid leukemia (AML), serum circRNA_100199 has the potential to be a promising prognostic biomarker, according to a study published in the International Journal of General Medicine. Research has indicated that an abnormal level of serum microRNA expression is a prognostic marker for AML. However, the significance of serum circRNA 100199 remained unknown, investigators noted. Therefore, they sought to examine the possible prognostic significance of serum circRNA_100199 for AML. A total of 200 participants consisting of 114 patients with AML and 86 controls were included in the study. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to measure the level of circRNA_100199 to determine the potential clinical significance, and blood samples were taken. The study team observed that in patients with AML, circRNA_100199 expression in the serum was significantly higher, compared with that of healthy controls. In patients with AML with M4/M5 subtype and those with higher white blood cell counts or poor cytogenetic risk, the increase in serum circRNA_100199 levels was especially obvious.