A cellulase variant, or active fragment thereof, having at least 95% amino acid sequence identity to the amino acid sequence of SEQ ID NO:1, wherein said variant has endoglucanase activity, wherein said variant comprises mutations at positions selected from: (i) Q36T-S77K-G87A-A142P-S153D-A161P-G204S-S221L-S237D, (ii) S23L-S32Y-G112T-A142P-A161P-G204S-S217G-K227R-S237D, (iii) K4V-S23L-S32Y-N80S-T102K-A142P-A161P-S237D, (iv) G87A-A142P-A161P-L192V-G204S-T241A, (v) Q36T-V98Y-A142P-A161E-S225K, (vi) A99Y-P136E-A142P-A161E-S221L, (vii) S32D-A99Y-A142P-A161E-S249P, (viii) K44V-A142P-A161P-K163V, (ix) S32D-Q36T-S77M-S135T-A142P-A161P, (x) K4V-G112S-S135T-A142P-A161P, (xi) P97S-G112V-P136S-A142P-A161E-K163V-P212S-S222A, (xii) K44V-A142P-A161P-K163V-K227R-T236A, (xiii) Q36T-S51T-V98G-T116V-A142P-A161P-T233S-Z233.01T-Z233.02A-Z233.03S-7233.04T-7233.05K-72233.06A-7233.07T-2233.0858-7233.09T-2233.10T, (xiv) Q36T-S77K-G87A-A142P-S153D-A161P-D177Z-G204S-S221L-S237D, and (xv) K4V-S32G-Q36T-S77M-G87A-T116V-A142P-A161P-Z233.01S-Z233.02T-7233.03T-7233.04D-7233.05T-7233.06K-72233.07A-7233.08T-7Z233.095-7233.10T-Z233.11T, wherein Z233.01T-Z233.02A-Z233.03S-Z233.04T-Z233.05K-Z233.06A-Z233.07T-Z233.08S-Z233.09T-Z233.10T is an insertion of TASTKATSTT after position 233, wherein D117Z is a deletion of D from position 117, wherein Z233.01S-Z233.02T-Z233.03T-Z233.04D-Z233.05T-Z233.06K-Z233.07A-7233.08T-Z233.098-72233.10T-Z233.11T is an insertion of STTDTKATSTT after position 223, wherein said positions correspond to SEQ ID NO:1 positions, and wherein said variant has at least one improved property selected from improved thermostability, stability in the presence of one or more protease, and stability in the presence of one or more protease and one or more other detergent component, when compared to a reference polypeptide of SEQ ID NO:1. (i) Q36T-S77K-G87A-A142P-S153D-A161P-G204S-S221L-S237D, (ii) S23L-S32Y-G112T-A142P-A161P-G204S-S217G-K227R-S237D, (iii) K4V-S23L-S32Y-N80S-T102K-A142P-A161P-S237D, (iv) G87A-A142P-A161P-L192V-G204S-T241A, (v) Q36T-V98Y-A142P-A161E-S225K, (vi) A99Y-P136E-A142P-A161E-S221L, (vii) S32D-A99Y-A142P-A161E-S249P, (viii) K44V-A142P-A161P-K163V, (ix) S32D-Q36T-S77M-S135T-A142P-A161P, (x) K4V-G112S-S135T-A142P-A161P, (xi) P97S-G112V-P136S-A142P-A161E-K163V-P212S-S222A, (xii) K44V-A142P-A161P-K163V-K227R-T236A, (xiii) Q36T-S51T-V98G-T116V-A142P-A161P-T233S-Z233.01T-Z233.02A-Z233.03S-7233.04T-7233.05K-72233.06A-7233.07T-2233.0858-7233.09T-2233.10T, (xiv) Q36T-S77K-G87A-A142P-S153D-A161P-D177Z-G204S-S221L-S237D, and (xv) K4V-S32G-Q36T-S77M-G87A-T116V-A142P-A161P-Z233.01S-Z233.02T-7233.03T-7233.04D-7233.05T-7233.06K-72233.07A-7233.08T-7Z233.095-7233.10T-Z233.11T, wherein Z233.01T-Z233.02A-Z233.03S-Z233.04T-Z233.05K-Z233.06A-Z233.07T-Z233.08S-Z233.09T-Z233.10T is an insertion of TASTKATSTT after position 233, wherein D117Z is a deletion of D from position 117, wherein Z233.01S-Z233.02T-Z233.03T-Z233.04D-Z233.05T-Z233.06K-Z233.07A-7233.08T-Z233.098-72233.10T-Z233.11T is an insertion of STTDTKATSTT after position 223, wherein said positions correspond to SEQ ID NO:1 positions, and wherein said variant has at least one improved property selected from improved thermostability, stability in the presence of one or more protease, and stability in the presence of one or more protease and one or more other detergent component, when compared to a reference polypeptide of SEQ ID NO:1.