PDGFRB and systemic sclerosis: In fact, aberrant PDGFR signaling drives pathological responses in the principal cellular executors of fibrosis, i.e., mesenchymal stromal cells such as fibroblasts, pericytes, and myofibroblasts, in diverse fibrotic diseases [12], including cardiac and pulmonary fibrosis, liver cirrhosis, glomerulosclerosis, and systemic sclerosis [30,31,32].