KRT17 and systemic sclerosis: 3 main subsets of macrophages: SPP1hi, FABP4hi and FCN1hi. Type I IFN signaling was upregulated in SSc-ILD, IFNγ signaling was upregulated in IPF. AT1 exhibited the most distinct expression patterns between IPF and SSc-ILD, KRT5-/KRT17+ aberrant basaloid cells were identified in SSc-ILD.