In recent years, studies on drug resistance in lung cancer have confirmed that the aberrant expression of endogenous miRNAs promotes or inhibits the production of MDR during LC drug therapy by regulating the ABC transporter of the PI3K/AKT pathway, the expression of apoptosis-associated proteins, nuclear factor κb (NF-κB), glycogen synthase kinase 3β (GSK-3β), and mTOR, among others (107). The gene discussed is PIK3CD; the disease is lung cancer.