miR-181a-5p promotes breast tumor progression through N-Myc downstream-regulated gene 2 (NDRG2)-induced activation of the PTEN/AKT signaling pathway and inhibition of sprouty RTK signaling antagonist 4 (SPRY4), PH domain, leucine-rich repeat protein phosphatase 2 (PHLPP2), and inositol polyphosphate 4-phosphatase type II (INPP4B) [29,30,31]. Here, SPRY4 is linked to breast neoplasm.