A polypeptide comprising an high mobility group-box (HMG-box) domain for use in a method for inhibiting, preventing or treating a microbial infection that produces a microbial biofilm in a subject by inhibiting, preventing or breaking down said microbial biofilm, wherein the polypeptide is: (i) a polypeptide comprising the high mobility group box domain of a polypeptide selected from the group of a high mobility group box protein 2 (HMGB2), a high mobility group box 3 protein (HMGB3), a high mobility group box 4 protein (HMGB4), a non-histone component of chromatin SRY (sex determining region Y protein), a SOX family of transcription factors, a sequence-specific LEF1 (lymphoid enhancing binding factor 1), a TCF-1 (T-cell factor 1), a structure-specific recognition protein SSRP involved in transcription and replication; a MTF1 mitochondrial transcription factor, a nucleolar transcription factors UBF 1/2 (upstream binding factor) involved in transcription by RNA polymerase I, Abf2 yeast ARS-binding factor, a yeast transcription factor selected from the group of lxr1, Rox1, Nhp6b and Spp41; a mating type protein involved in the sexual reproduction of fungi, a YABBY plant-specific transcription factor; or (ii) a polypeptide having at least 80% sequence identity to the high mobility group box domain of a polypeptide selected from the group of a high mobility group box protein 2 (HMGB2), a high mobility group box 3 protein (HMGB3), a high mobility group box 4 protein (HMGB4), a non-histone component of chromatin SRY (sex determining region Y protein), a SOX family of transcription factors, a sequence-specific LEF1 (lymphoid enhancing binding factor 1), a TCF-1 (T-cell factor 1), a structure-specific recognition protein SSRP involved in transcription and replication; a MTF1 mitochondrial transcription factor, a nucleolar transcription factors UBF 1/2 (upstream binding factor) involved in transcription by RNA polymerase I, Abf2 yeast ARS-binding factor, a yeast transcription factor selected from the group of lxr1, Rox1, Nhp6b and Spp41; a mating type protein involved in the sexual reproduction of fungi, a YABBY plant-specific transcription factor; wherein the method comprises administering to the subject an effective amount of the polypeptide. (i) a polypeptide comprising the high mobility group box domain of a polypeptide selected from the group of a high mobility group box protein 2 (HMGB2), a high mobility group box 3 protein (HMGB3), a high mobility group box 4 protein (HMGB4), a non-histone component of chromatin SRY (sex determining region Y protein), a SOX family of transcription factors, a sequence-specific LEF1 (lymphoid enhancing binding factor 1), a TCF-1 (T-cell factor 1), a structure-specific recognition protein SSRP involved in transcription and replication; a MTF1 mitochondrial transcription factor, a nucleolar transcription factors UBF 1/2 (upstream binding factor) involved in transcription by RNA polymerase I, Abf2 yeast ARS-binding factor, a yeast transcription factor selected from the group of lxr1, Rox1, Nhp6b and Spp41; a mating type protein involved in the sexual reproduction of fungi, a YABBY plant-specific transcription factor; or (ii) a polypeptide having at least 80% sequence identity to the high mobility group box domain of a polypeptide selected from the group of a high mobility group box protein 2 (HMGB2), a high mobility group box 3 protein (HMGB3), a high mobility group box 4 protein (HMGB4), a non-histone component of chromatin SRY (sex determining region Y protein), a SOX family of transcription factors, a sequence-specific LEF1 (lymphoid enhancing binding factor 1), a TCF-1 (T-cell factor 1), a structure-specific recognition protein SSRP involved in transcription and replication; a MTF1 mitochondrial transcription factor, a nucleolar transcription factors UBF 1/2 (upstream binding factor) involved in transcription by RNA polymerase I, Abf2 yeast ARS-binding factor, a yeast transcription factor selected from the group of lxr1, Rox1, Nhp6b and Spp41; a mating type protein involved in the sexual reproduction of fungi, a YABBY plant-specific transcription factor;