circFAM120B inhibits OS progression via miR-1205/PTBP1 signaling. OS cells transfected with si-circFAM120B or co-transfected with miR-1205 inhibitors or co-transfected with PTBP1. (A) PTBP1 mRNA levels in OS cells. (B–D) Expression correlations between circFAM120B, miR-1205, and PTBP1 in OS tissues. (E) Colony formation assay. (F) Transwell invasion assay. *P < 0.05.