As such, this tool may have utility as a predictor of therapeutic response.129 The first in-human Phase I trial using CD8 minibodies was performed in six patients and found administration to be safe (Figure 5).130 Furthermore, tumour uptake occurred within 2 h of administration and in one melanoma patient, PET signal matched with pathologically confirmed intratumoral CD8 T cell infiltration. Here, CD8A is linked to neoplasm.