ACVR1 and cancer: Flow cytometry analysis revealed the ratio of cancer side population (SP) cells with CSC-like properties was 0.62% (Fig. 1i), while the RT-qPCR, results as depicted in Fig. 1j demonstrated that the expression of AFAP1-AS1 and ACVR1 was significantly decreased while the expression of the CSC markers Oct4, ABCG2, Nestin, CK19 and CD133 in non-SP cells compared with that in SP cells was diminished (p < 0.05).