CD34 and systemic sclerosis: Thus far, abnormalities in TCs/CD34+ stromal cells have been reported in a variety of skin pathologies, ranging from tumor and tumor-like conditions to inflammatory and fibrosing/sclerosing diseases such as systemic sclerosis (SSc, scleroderma), a complex connective tissue disease in which immune system disturbances and microvascular injury evolve into progressive generalized fibrosis of the skin and internal organs [23,28,29,30,31,32,33,34,35,36].