CEACAM6 and lung adenocarcinoma: To determine whether the pHLIP-PNA miR-29a conjugate could efficiently deliver miR-29a to cells and target CEACAM6, A549 lung adenocarcinoma cells were incubated for 48 h at pH 6.2 with 100, 250, or 500 nM pHLIP-miR-29a or pHLIP-scr as a control.