Moreover, since cysteine cathepsins derive from both tumor cells and tumor-stromal cells, such as TAMs, cathepsin-targeted probes will potentially result in a more homogeneous tumor signal compared to probes targeting tumor cell-specific proteins, such as epidermal growth factor receptor (EGFR), that often display high intratumor and interpatient heterogeneity [125, 126]. The gene discussed is CTSS; the disease is neoplasm.