YBX1 and breast cancer: Under hypoxic conditions, BC cell lines produce a series of tRFs that reduce the stability of multiple oncogenic transcripts by competitively binding the 3′-UTRs of the RBP Y-box binding protein 1 (YBX1), which decreased the expression of oncogenes in the post-transcriptional pathway, leading to the suppression of tumor growth [20] (Fig. 2b).