The present invention relates to an isolated DNA which codes for a gene essential for cell wall glucan synthesis of Candida albicans, wherein the gene is referred to as CaKRE9, wherein the sequence of the DNA is as set forth in Fig. 1. The present invention relates to antifungal in vitro and in vivo screening assays for identifying compounds which inhibit the synthesis, assembly and/or regulation of beta 1,6-glucan. There is also disclosed an in vitro method for the diagnosis of diseases caused by fungal infection in a patient.