Method of identifying an anti-fungal agent which targets as an essential protein or gene of a fungus comprising contacting a candidate substance with (i) a protein which comprises the sequence shown by SEQ ID NOS: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 50, 53, 56, 59, 61 or 63, or (ii) a protein which has 60% identity with (i), or (iii) a protein comprising a fragment of (i) or (ii) which fragment has a length of at least 50 amino acids, or (iv) a polynucleotide that comprises a sequence which encodes (i), (ii) or (iii), or (v) a polynucleotide comprising a sequence which has at least 70% identity with the coding sequence of (iv), and determining whether the candidate substance binds or modulates (i), (ii), (iii), (iv), or (v), wherein binding or modulation of (i), (ii), (iii), (iv), or (v) indicates that the candidate substance is an anti-fungal agent.