FOLH1 and cancer: A recent study in breast cancer highlighted that specific PSMA isoforms may be selectively and highly expressed among breast cancer stem cells (BCSCs), which represent a subpopulation of tumor cells that promote cancer recurrence and progression due to their multi-potency and self-renewing capacity [39] Notably, BCSCs showed greater uptake of radiolabeled PSMA, consistent with higher expression relative to the remaining non-stem tumor cell populations.