Cells communicate by sending signalling ligands which attack to receptors on other cells. In order for a cell to send these molecules, they must be able to pass through its membrane. If cells were completely impermeable, molecules, including those used for communication, could not leave them. Cells have semi-permeable membranes, so while some compounds are allowed to enter and leave, others are blocked.
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence