PTGDR and osteosarcoma: Among these 10 proteins, Smad nuclear interacting protein 1 (SNIP1) is reported to promote or inhibit the transcription of target genes through binding to different histone modification complexes or transcription factors.34–38 It was highly expressed in several tumors, such as non-small cell lung cancer and osteosarcoma.39–41 Our western blotting confirmed that AFAP1-AS1 could combine with SNIP1 protein, while the antisense string of AFAP1-AS1 and a negative control PFN could not (Fig. 3d).