Tissue Modeling in Systemic Sclerosis Using Induced Pluripotent Stem Cells (iPSCs)

Inclusion Criteria: * Age between 18 and 85 years * Diagnostic criteria for the three groups: \> Severe SSc group: * Diagnosis of diffuse/severe systemic sclerosis by a physician for at least 12 months based on recommendations (according to ACR criteria) * Known positivity of autoimmunity directed against Scl-70 \> Localized/non-complicated SSc group: * Diagnosis of systemic sclerosis by a physician for at least 12 months based on recommendations (according to ACR criteria) * Documentation of the absence of major vital organ involvement * Negative anti-Scl-70 autoantibodies but presence of other systemic sclerosis-related autoantibodies \> Healthy subjects group: * First-degree relative of a patient recruited in one of the systemic sclerosis groups (father, mother, brother, sister, adult child) * Absence of systemic autoimmune diseases Exclusion Criteria: * Other diseases that may affect erythroid progenitor cells (non-exhaustive: active cancer, hematological malignancy, chemotherapy targeting DNA) * Patient in an exclusion period determined by another protocol * Protected populations according to French public health law (pregnant or breastfeeding women; individuals deprived of liberty by judicial or administrative decision; adults under legal protection (any form of guardianship)) * Absence of informed consent * Not affiliated with a national health insurance system