This document proposes a therapy to eradicate solid tumors using genetically engineered capillary endothelial progenitor cells. The cells will be modified to contain a suicide gene regulated by a chimeric prolactin receptor and loaded with toxin-containing microcapsules. When administered to a patient, the cells will home to tumor sites where prolactin is produced, activate the suicide gene, and release toxins from ruptured microcapsules to destroy the tumor through a "bystander effect". The therapy aims to selectively target cancerous regions while sparing healthy tissue.