In contrast to the C24D-induced immune reactivation observed in PBMCs from COVID-19 patients, no significant effect was seen on Lck (Y505, p < 0.122; Y394, p < 0.301), ZAP70 (p < 0.08) and VAV-1 (p < 0.274) phosphorylation when fresh PBMCs from healthy donors were incubated with C24D for 5 min to 24 h (Figure 1A). Here, LCK is linked to COVID-19.