TGFB1 and cancer: MiR-21 has also been linked with inflammation-related cancers, in which its expression is stimulated by inflammatory factors such as interleukin 6 (IL-6) [17], signal transducer and activator of a transcription 3 (STAT3)-dependent mechanism [18], and transforming growth factor (TGF-β) through the SMADs signaling cascade [19].