Analyzed factors included mechanic's hands (yes vs. no), skin ulceration (yes vs. no), periungual erythema (yes vs. no), fever (yes vs. no), anti-MDA5 antibody (positive vs. negative), anti-Ro-52 antibody (positive vs. negative), and elevated CRP (yes vs. no) (Table 1). This evidence concerns the gene TRIM21 and Erythema.