The EWC-1 model is trained using the direct peptide reactivity assay (DPRA) and Human cell line activation assay data(h-CLAT) data. The DPRA assay is an in-chemo assay that measures a substance's ability to form a hapten-protein complex while the human Cell line activation assay is an in-vitro test that accesses the ability of a substance to induce or mobilize dendric cells in the skin. Results from DPRA reflect the molecular initiating event in AOP for skin sensitization the first key event in Skin Sensitization Adverse outcome pathway. Both tests are part of the integrated testing strategies for skin sensitization as stipulated by OECD.