In Plummer-Vinson syndrome, the region involved is
Plummer-Vinson syndrome (PVS), a rare clinical condition, is characterized by a triad of dysphagia, iron deficiency anemia and esophageal web in the post-cricoid region. Ref ganong's review of medical physiology 25e 676
Posterior pharyngeal wall
Valleculae
Postcricoid region
Pyriform sinus
All India exam