IL7 and lymphopenia: In human studies, recombinant IL-7 (non-glycosylated and glycosylated), and a pharmacokinetic (PK)-enhanced Fc-fusion of IL-7 (efineptakin alfa) have been clinically evaluated for use in lymphopenia, septic shock, infectious disease, enhancement of response to vaccination, lymphopenia associated with COVID-19, autoimmune diseases, chronic inflammatory diseases, and cancer.