ENO2 and small cell lung carcinoma: A comparative evaluation of one or more available biomarkers, such as CEA, CYFRA 21-1, TAG72-3, neuron-specific enolase (NSE), and squamous cell carcinoma antigen (SCC), along with the MUC1/CA15-3 and MUC16/CA125 mucins, has provided a platform for the early detection of NSCLC and its differentiation from SCLC [105].