PTBP1 and colorectal carcinoma: circRHOBTB3 (hsa_circ_0007444) directly binds to HuR to accelerate its ubiquitination and degradation induced by the E3 ubiquitin ligase β-Trcp1, limiting the mRNA expression of PTBP1, a target of HuR, and thereby abolishing PTBP1-induced CRC metastasis [19].