When we evaluated the number of CD68+ myeloid cells, which encompass alveolar macrophages, monocytes/interstitial macrophages, and histiocytes [72, 73], for the expression of FLIP, COVID-19 samples displayed a variable number of FLIP-expressing CD68+ cells (Fig. 1A, second line) suggesting an accumulation of FLIP+ myeloid cells during COVID-19 progression. This evidence concerns the gene CD68 and COVID-19.