SP1 and cancer: Furthermore, SP1 regulates the TGF‐β signalling pathway in cancer cells.[31] Our data demonstrate that the low expression of circTAX1BP1 diminishes the upregulation of TGF‐β, p‐Smad2, p‐Smad3, and SP1 induced by CAF‐derived EVs (Figure 5M; Figure S9F,G, Supporting Information).