CALR and scleroderma: In addition, the five patients tested negative for rheumatoid factor, anticardiolipin antibodies, cryoglobulins, perinuclear antineutrophil cytoplasmic antibodies, antinuclear antibodies (anti-Ro), antiphospholipid antibodies, anti-double-stranded DNA antibodies, anti-Smith antibodies, anti-nuclear ribonucleoprotein antibodies, and anti-Scleroderma-70 antibodies.