For example, circDENND2A is overexpressed in glioma cells under hypoxia and promotes the migration and invasion of glioma cells via sponging miR‐625‐5p.[15] And we reported that circTDRD3 is upregulated under hypoxic conditions, promoting the growth and metastasis of colorectal cancer cells through a positive HIF1A/PTBP1/circTDRD3/miR‐1231/HIF1A feedback loop.[16] While current research on hypoxia‐related circRNAs largely centers on their miRNA‐sponging activity, alternative functional mechanisms remain unexplored. The gene discussed is PTBP1; the disease is central nervous system cancer.