Hyperinflammatory states may benefit from targeted cytokine inhibition, whereas immunosuppressed phenotypes marked by reduced monocyte HLA-DR (human leukocyte antigen-DR) expression, lymphopenia, and T-cell exhaustion may require immunostimulatory therapies such as GM-CSF (granulocyte-colony stimulating factor), interferon-γ, or interleukin-7. Here, CSF3 is linked to lymphopenia.