MUC1 and incontinentia pigmenti: In our cohort, which comprised only patients with SLE and IP, current smoking, serum KL-6, and NSIP + OP pattern on HRCT (vs. NSIP pattern) were significant prognostic factors according to multivariate Cox proportional hazards analyses, as were comorbid other CTDs, thrombocytopenia, and anti-dsDNA antibody titre.