The tumor-suppressive activity of circRHOBTB3 in CRC implies the regulation of metabolic pathways and intracellular reactive oxygen species levels as well as the binding of HuR (Hu-antigen R/ELAV-like protein 1), favoring ubiquitination and degradation of this RNA-binding protein and the downmodulation of the RNA splicing factor PTBP1 (polypyrimidine tract-binding protein 1) [73,74]. The gene discussed is PTBP1; the disease is colorectal carcinoma.