ACTN1 and COVID-19: ACTN1, a cytoskeletalactin-binding protein, interacts with multipleSARS-COV-2 proteins,101 and increased ACTN1expression has been linked to increased cell adhesion, which playsa significant role in the development and progression of Omicron infection.65 High levels of ACTN1 in urine and plasma havebeen associated with nonsevere COVID-19 (Shu_1, Li J._1, Bi_3).102−104 Interestingly, increased levels have also been observed in salivarysamples from convalescent COVID-19 patients.