Higher CRP levels (β = 0.304, P = 0.003), serositis (β = 0.321; P = 0.002), and previous positivity for anti-RNP antibodies (β = 0.297; P = 0.003) were found to be independently associated with anti-Sm levels in patients with SLE (Table 4). Here, RNPC3 is linked to systemic lupus erythematosus.