Such tumors are further subdivided on basis of various other parameters such as mucin staining, various markers analyzed by molecular data and immunohisto/cytochemistry.9, 10 Various new marker genetic alterations are recommended now in the panel of molecular testing to classify NSCLC including mutations in epidermal growth factor receptor (EGFR), B‐Raf proto‐oncogene (BRAF), and the expression of programmed death ligand 1 (PD‐L1) in small biopsy samples and cytologic specimens 11, 12, 13, 14 (Figure 1). Here, MUC5AC is linked to non-small cell lung carcinoma.