Letter to the Editor Regarding "An Overview on Serology and Molecular Tests for COVID-19: An Important Challenge of the Current Century (doi: 10.22034/iji.2021.88660.1894.)".

Recently in a review article by Mansourabadi et al. published in the Iranian Journal of Immunology, the authors described the serological and molecular tests for COVID-19 (1). The mentioned review considered helicase (Hel) as a structural protein of SARS-CoV-2 (1). However, based on evidence, the genome of novel coronavirus is approximately 30kb in length and encodes only four structural proteins, including spike (S), envelope (E), membrane (M), and nucleoprotein (N) (2, 3), although helicase (NSP13) as a nonstructural protein such as RNA-dependent RNA polymerases (NSP12) encoded by the ORF region and is involved in the replication of the virus (3).In addition, authors reported that hemagglutinin esterase could be used as a favorite target for SARS-CoV-2 Real-time PCR (1); however, scientific evidence shows that SARS-CoV-2 as a betacoronavirus lineage B like SARS-CoV lacks hemagglutinin esterase (4-6); thus this protein cannot be a target for detection of SARS-CoV-2.