SP1 and posterior cortical atrophy: Further, we found that SMAD3/SP1 transcriptional complex‐induced overexpression of PCAT7 upregulated TGFBR1 expression by sponging miR‐324‐5p as a ceRNA, which led to the unrestrained activation of TGF‐β pathway, which reciprocally promoted PCa bone metastasis.