Appeal from a decision of the Unemployment Insurance Appeal Board, filed January 7, 1976, which affirmed the decision of a referee sustaining an initial determination of the Industrial Commissioner disqualifying claimant from receiving benefits effective August 24, 1975 because she lost her employment through misconduct. The determination of the issue of misconduct is a factual one (Matter of Desvaux [Levine], 49 A.D.2d 778). When such a determination is supported by substantial evidence, it must be affirmed (Matter of Lester [Catherwood], 30 A.D.2d 1025). Claimant's admitted alteration of the doctor's certificate provides the substantial evidence here. Decision affirmed, without costs. Koreman, P.J., Greenblott, Sweeney, Main and Larkin, JJ., concur.