PDCD4 and breast cancer: The tumor-suppressor PDCD4 was identified as a potential miR-206 targeted transcript by multiple miR-target prediction tools.37, 56 PDCD4 is a negative regulator of RAS-ERK-AP1 signaling and protein translation, and promotes breast cancer cell apoptosis.57, 58, 59 We therefore analyzed PDCD4 as a miR-206-regulated transcript.