PDCD4 and breast carcinoma: Additionally, miR-21 links EMT and inflammatory signals (IL-6/STAT3/NF-κB-mediated signaling loop and activating the PI3K pathway) to confer resistance to trastuzumab and chemotherapy in HER2-positive breast cancer patients through downregulation of PTEN and programmed cell death 4 (PDCD4) [197].