Abstract: Provided herein are tandem Fcs and tandem Fc antibodies (“TFcAs”), e.g., tandem Fc bispecific antibodies (“TFcBAs”), which comprise one or at least two binding sites that specifically bind to one or more cell surface receptors. The binding sites are connected through a TFc, which TFc comprises a first Fc region and a second Fc region, wherein the first and the second Fc regions are linked through a TFc linker to form a contiguous polypeptide and dimerize to form an Fc dimer. Exemplary TFcBAs bind to the cell surface receptors c-Met and EpCam and inhibit signal transduction through the cell surface receptor(s) for which the binding sites of the TFcBA are specific.

Abstract: The present invention overcomes the inadequacies inherent in the known methods for generating libraries of antibody-encoding polynucleotides by specifically designing the libraries with directed sequence and length diversity. The libraries are designed to reflect the preimmune repertoire naturally created by the human immune system, with or without DH segments derived from other species, and are based on rational design informed by examination of publicly available databases of antibody sequences.

Abstract: The present invention overcomes the inadequacies inherent in the known methods for generating libraries of antibody-encoding polynucleotides by specifically designing the libraries with directed sequence and length diversity. The libraries are designed to reflect the preimmune repertoire naturally created by the human immune system and are based on rational design informed by examination of publicly available databases of human antibody sequences.

Abstract: The present invention overcomes the inadequacies inherent in the known methods for generating libraries of antibody-encoding polynucleotides by specifically designing the libraries with directed sequence and length diversity.

Abstract: Compositions are provided that comprise antibody against membrane proteins such as chemokine receptors. In particular, monoclonal human antibodies against human CXCR4 are provided that are capable of inhibiting HIV infection and chemotaxis in human breast cancer cells. The antibodies can be used as prophylactics or therapeutics to prevent and treat HIV infection and cancer, for screening drugs, and for diagnosing diseases or conditions associated with interactions with chemokine receptors.

Abstract: Anti-EGFR antibodies, therapeutic compositions comprising combinations of anti-EGFR antibodies, as well as methods for using such antibodies and compositions to treat EGFR-related disorders (e.g., cancers), are disclosed.