The glucan synthesis inhibitors are, collectively, agents which are presumed to block fungal cell wall synthesis by inhibiting the enzyme 1,3-beta glucan synthase. As technical issues in the laboratory have made formal proof of the assertion that this enzyme is actual target of these compounds, it is most correct to speak of them at present as being glucan synthesis inhibitors rather than glucan synthase inhibitors. There are three such agents at present, with all three belonging to the chemical family also known as the echinocandins.