Another group utilized ovarian cancer PDX models and found a promising therapeutic target Ephrin-A4 (EFNA4) with the identification of E-cadherin (CD324) as a surface antigen able to enrich TIC, and revealed that an antibody-drug conjugate (ADC) containing anti-EFNA4 monoclonal antibody conjugated to the DNA-damaging agent calicheamicin inhibited tumor growth 88. Here, EFNA4 is linked to ovarian cancer.