Recently, Coulis et al., through a combination of single-cell and spatial transcriptomics approaches, identified a predominant profibrotic macrophage cluster expressing the fibrotic markers galectin3 (Lgals3), Triggering Receptor Expressed on Myeloid Cells 2 (Trem)2, and cathepsins -d, -l and -s (Cts-d, -l, and -s) as well as osteospontin (Spp1) and transmembrane glycoprotein nmb (Gpnmb) in the dystrophic muscles of a Duchenne dystrophy myopathy (DMD) mdx mouse model and in human DMD muscles [15]. The gene discussed is CTSD; the disease is Duchenne muscular dystrophy.