IPF and SSc-ILD myeloid and lymphoid cells exhibited disparate patterns of interferon signaling, with IFN-γ signaling amplified in IPF SPP1hi and FABP4hi macrophages and cytotoxic T and natural killer cells, while Type 1 IFN signaling was amplified in the analogous SSc-ILD populations. The gene discussed is IFNG; the disease is idiopathic pulmonary fibrosis.