<prompt> A 17-year-old boy presented with TLC of 138 x 109 L with 80 blasts on the peripheral smear. Chest X-ray demosnstrated a large mediastinal mass. Immunophenotyping of this patient;s blasts would most likely demonstrate -No surface antigens null phenotypeAn immature T cell phenotype TdtD34CD7 positiveMyeloid markers, such as CD 13, CD33 and CD 15B cell markers, such as CD 19, CD20 and CD22  <response>: The cluster of differentiation also known ascluster of designation or classification determinant and often abbreted as CD is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophenotyping of cells. 