In recent years, PCM models have emerged in the literature as promising tools for identifying novel drug candidates for orphan targets(4), as is the case with GPCRs. Given the challenges associated with SLCs, as highlighted above, the potential of PCM in screening drug candidates for orphan SLC6 members becomes particularly intriguing. As part of our approach, we excluded one SLC6 member at a time during model training and focused on the remaining targets. This method was used to validate the model's ability to predict activities against the omitted target.