Decreased synthetic activity in IPF and PASC-F myeloid cells was observed following the analysis of several soluble pro-inflammatory and pro-fibrotic mediators, as shown in Figure 3A. The one exception among the mediators analyzed was the pro-fibrotic factor chitinase 3-like 1, which was elevated in cultures of both IPF and PASC-F myeloid cells compared with healthy donor myeloid cells (Figure 3A). Here, CHI3L1 is linked to idiopathic pulmonary fibrosis.