MiR‐21 targets anti‐oncogenes and metastasis‐suppressing genes, like programmed cell death 4 (PDCD4), tumour‐suppressor gene tropomyosin 1 (TPM1), phosphatase and tensin homologue (PTEN) and Sprouty, thereby demonstrating its involvement in cancer growth, invasiveness and metastasis 16. Here, PDCD4 is linked to cancer.