NOVELTY - A nucleic acid comprising an expression cassette, which comprises operably linked in 5'-3' direction (a) strong promoter that is constitutively expressed in plant cells, (b) 5' untranslated region (UTR) operable in filamentous fungi, (c) first polypeptide coding sequence comprising a start codon and a stop codon, and (d) a 3' UTR, is new.    USE - The nucleic acid is useful in vector for preparing filamentous fungal cell used for producing recombinant polypeptide, secreted polypeptide and cellulase composition which is used for saccharifying biomass for producing a fermentation product, preferably fermentable sugars comprising disaccharides or monosaccharides, and ethanol. The fungal cell is species of Acremonium, Aspergillus, Emericella, Fusarium, Humicola, Mucor, Myceliophthora, Neurospora, Penicillium, Scytalidium, Thielavia, Chrysosporium, Phanerochaete, Tolypocladium, or Trichoderma, preferably A.awamori, A.fumigatus, A.foetidus, A.japonicus, A.nidulans, A.niger, A.oryzae, C.lucknowense, F.bactridioides, F.cerealis, F.crookwellense, F.culmorum, F.graminearum, F.graminum, F.heterosporum, F.negundi, F.oxysporum, F.reticulatum, F.roseum, F.sambucinum, F.sarcochroum, F.sporotrichioides, F.sulphureum, F.torulosum, F.trichothecioides, F.venenatum, H.insolens, H.lanuginosa, M.miehei, M.thermophila, N.crassa, N.intermedia, P.purpurogenum, P.canescens, P.solitum, P.funiculosum, P.chrysosporium, P.radiate, Pleurotus eryngii, T.terrestris, T.harzianum, T.longibrachiatum, T.reesei, or T.viride (all claimed). The polypeptide includes therapeutic polypeptides e.g. erythropoietin, cytokines immunoglobulin (Ig)G, interleukins and epidermal growth factor. The saccharified biomass is also useful for producing fuel including biofuel such as bioethanol, biobutanol, biomethanol, biopropanol, biodiesel, or jet fuel, and commodity chemical e.g. ascorbic acid, isoprene and 1,3-propanediol, lipids, amino acids, polypeptides, and enzymes.    ADVANTAGE - The nucleic acid enables simplified production of large quantities of commercially valuable proteins, provides expression systems that are economically viable and provide robust expression in large scale commercial fermentations, and enables to increase the yield of active polypeptide expressed in filamentous fungal cell.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) vector comprising the above-mentioned nucleic acid;    (2) filamentous fungal cell comprising the above-mentioned recombinant expression cassette;    (3) method (M1) for producing a recombinant polypeptide, involves culturing the above-mentioned filamentous fungal cell under conditions that result in expression of the first polypeptide;    (4) method (M2) for producing a secreted polypeptide, involves culturing the above-mentioned filamentous fungal cell under conditions that result in expression and secretion of the first polypeptide;    (5) method (M3) for producing a cellulase composition, involves (a) culturing the above-mentioned filamentous fungal cell under conditions that result in expression of the first protein, or (b) culturing the above-mentioned filamentous fungal cell under conditions that result in expression of the second protein;    (6) method (M4) for saccharifying biomass, involves (a) producing a cellulase composition by the method (M3), and (b) treating biomass with the cellulase composition; and    (7) method (M5) for producing a fermentation product, involves (a) producing the cellulase composition by the method (M3), (b) treating biomass with the cellulase composition, thus producing fermentable sugars, and (c) culturing a fermenting microorganism in the presence of the fermentable sugars under fermentation conditions.