ATM and mixed connective tissue disease: ACA aligns with lower ILD risk but higher PAH and digital vasculopathy; ATA predicts ILD onset/progression; RNAP III marks rapid skin thickening, SRC risk, and temporally clustered malignancy; U1 RNP tracks overlap/MCTD-like features and PAH; U3 RNP indicates diffuse disease with vasculopathy; Th/To varies by center; PM-Scl and Ku flag overlap ILD/myositis.