In view of our findings here and the results of Scott et al. [6], showing that miR-125a blocked ERK1/2 and Akt signaling in breast cancer cells, we will determine whether miR-125a-5p regulates the phosphorylation of Akt and/or ERK1/2 in lung cancer cells, and whether miR-125a-5p downregulates ErbB2 and ErbB3 in lung cancer cells, because the present work only focused on the functional analysis of miR-125-a-5p. This evidence concerns the gene MAPK3 and breast cancer.