ACSL1 and severe acute respiratory syndrome: Similarly, the Ingenuity Pathway Analysis (IPA) classification platform connected several proteins up- and downregulated in response to the asymptomatic serum factors to viral infection, apoptosis and autophagy (Table S6) and, in the case of the ECFCs+PCR group, protein changes were specifically associated with severe acute respiratory syndrome (ACSL1, MZT1, ZSWIM8) (Figure 4D).