Update information. The spider major ampullate gland and silkworm silk gland have similar morphological structure and function, so we explored whether there are some common protein components on silks, with three biological replicates for each sample. Dragline silk samples from mature female Trichonephila clavata spider and cocoon samples are from silkworm Bombyx mori chain. The dragline silk of the spider T. clavata and cocoon silk of the silkworm B. mori were cut with scissors. First, silk samples (20 mg of each sample) were dissolved in 500 μL of 9 M LiSCN, and the supernatant was collected after centrifugation (10,000 × g, 10 min). Protein concentrations were measured via the Bradford protein assay (Beyotime, China). Then, the samples were diluted 10-fold in an 8 M urea solution, mixed with 5 × SDS–PAGE buffer, and separated using a NuPAGE 4–12% Bis-Tris protein gel (Thermo Fisher Scientific, USA). The samples were subsequently digested using trypsin, and peptides were measured via LC–MS/MS on a Q Exactive HF-X column.