To explore the role of calpain in myeloid cells in bleomycin model of SSc, we crossed Capns1 floxed mice with LYZ-Cre transgenic mice to produced mice which were deficient for both calpain-1 and calpain-2 in the myeloid Capns1-ko lineages. The gene discussed is CAPNS1; the disease is systemic sclerosis.