A binding molecule comprising first and second polypeptide chains, wherein said first polypeptide chain comprises a VH1- n-VH2-C- n, wherein VH1 is a first heavy chain variable domain obtained from a first parent antibody or antigen binding portion thereof; VH2 is a second heavy chain variable domain obtained from a second parent antibody or antigen binding portion thereof; C is a heavy chain constant domain; n of the first polypeptide is a linker, wherein said n of the first polypeptide is either present or absent; and n of the first polypeptide is an Fc region, wherein said n of the first polypeptide is either present or absent; and wherein said second polypeptide chain comprises a VL1- n-VL2-C- n, wherein VL1 is a first light chain variable domain obtained from a first parent antibody or antigen binding portion thereof; VL2 is a second light chain variable domain obtained from a second parent antibody or antigen binding portion thereof; C is a light chain constant domain; n of the second polypeptide is a linker, wherein said n of the second polypeptide is either present or absent; and n of the second polypeptide does not comprise an Fc region, wherein said n of the second polypeptide is either present or absent, wherein the binding molecule specifically binds sclerostin and DKK-1 wherein the first polypeptide comprises a VH comprising 3 CDRs selected from the group consisting of SEQ ID NOs: a) 100, 101, 102; b) 204, 205, 206; c) 212, 213, 214; and d) 220, 221, 222, and wherein the second polypeptide comprises a VH comprising 3 CDRs selected from the group consisting of SEQ ID NOs: a) 228, 229, 230; b) 236, 237, 238; c) 244, 245, 246; d) 252, 253, 254; e) 260, 261, 262; f) 268, 269, 270; g) 276, 277, 278; h) 284, 285, 286; i) 292, 293, 294; j) 300, 301, 302; k) 308, 309, 310; l) 316, 317, 318; m) 324, 325, 326; n) 332, 333, 334; o) 340, 341, 342; p) 348,349,350; q) 356, 357, 358; r) 364, 365, 366; s) 372,373,374; t) 380, 381, 382; u) 388, 389, 390; v) 396, 397, 398; w) 404, 405, 406; and x) 412, 413, 414 and/or wherein the second polypeptide comprises VL comprising 3 CDRs selected from the group consisting of SEQ ID NOs: a) 97, 98, 99; b) 201, 202, 203; c) 209, 210, 211; and d) 217, 218, 219, and wherein the second polypeptide comprises a VL comprising 3 CDRs selected from the group consisting of SEQ ID NOs: a) 225, 226, 227; b) 233, 234, 235; c) 241, 242, 243; d) 249, 250, 251; e) 257, 258, 259; f) 265, 266, 267; g) 273,274,275; h) 281, 282, 283; i) 289, 290, 291; j) 297, 298, 299; k) 305, 306, 307; l) 313, 314, 315; m) 321, 322, 323; n) 329, 330, 331; o) 337,338,339; p) 345, 346, 347; q) 353, 354, 355; r) 361, 362, 363; s) 369, 370, 371; t) 377, 378, 379; u) 385, 386, 387; v) 393, 394, 395; w) 401, 402, 403; and x) 409, 410, 411. a) 100, 101, 102; b) 204, 205, 206; c) 212, 213, 214; and d) 220, 221, 222, a) 228, 229, 230; b) 236, 237, 238; c) 244, 245, 246; d) 252, 253, 254; e) 260, 261, 262; f) 268, 269, 270; g) 276, 277, 278; h) 284, 285, 286; i) 292, 293, 294; j) 300, 301, 302; k) 308, 309, 310; l) 316, 317, 318; m) 324, 325, 326; n) 332, 333, 334; o) 340, 341, 342; p) 348,349,350; q) 356, 357, 358; r) 364, 365, 366; s) 372,373,374; t) 380, 381, 382; u) 388, 389, 390; v) 396, 397, 398; w) 404, 405, 406; and x) 412, 413, 414 a) 97, 98, 99; b) 201, 202, 203; c) 209, 210, 211; and d) 217, 218, 219, a) 225, 226, 227; b) 233, 234, 235; c) 241, 242, 243; d) 249, 250, 251; e) 257, 258, 259; f) 265, 266, 267; g) 273,274,275; h) 281, 282, 283; i) 289, 290, 291; j) 297, 298, 299; k) 305, 306, 307; l) 313, 314, 315; m) 321, 322, 323; n) 329, 330, 331; o) 337,338,339; p) 345, 346, 347; q) 353, 354, 355; r) 361, 362, 363; s) 369, 370, 371; t) 377, 378, 379; u) 385, 386, 387; v) 393, 394, 395; w) 401, 402, 403; and x) 409, 410, 411.