One type SorCS1 agent for use in treating insulin resistance and / or related to insulin resistance in an individual disease, wherein said agent is selected from the group consisting of: a) an isolated soluble SorCS1 polypeptide selected the group consisting of i) an amino acid sequence consisting of SEQ ID NO: 5, 10, 15, 21, 27 and 33 ii) a variant of biologically active sequence or an allelic variant of naturally occurring amino acid sequence of i) wherein the variant has at least 70% sequence identity with respect to said SEQ ID NO. 5, 10, 15, 21, 27 or 33 or iii) a biologically active fragment comprising an amino acid sequence selected from the group consisting of: SEQ ID NO: 1 aa 103-124, SEQ ID NO: 1 aa 125-143, SEQ ID NO: 1 aa 144-162, SEQ ID NO: 1 aa 197-218, SEQ ID NO: 1 aa 391-409, SEQ ID NO: 1 aa 661-684 and SEQ ID NO: 1 aa 763-783, SEQ ID NO: 1 aa 859-876 or a variant of said fragment, wherein the variant has at least 70% sequence identity with respect to said SEQ ID NO: 1 aa 103-124, SEQ ID NO: 1 aa 125-143, SEQ ID NO: 1 aa 144-162, SEQ ID NO: 1 aa 197-218, SEQ ID NO 20: 1 aa 391-409, SEQ ID NO: 1 aa 661-684 and SEQ ID NO: 1 aa 763-783, SEQ ID NO: 1 aa 859-876 wherein said SorCS1 soluble polypeptide isolated is capable of binding to the insulin receptor in a binding site to SorCS1 and is capable of raising an insulin receptor, and wherein the biological activity is the sensitization of an insulin receptor, b) a sequence nucleic acid encoding a polypeptide as defined in a) c) an expression vector comprising the nucleic acid molecule as defined in b), d) an isolated host cell transformed or transduced with the nucleic acid of b) or vector c).Un agente tipo SorCS1 para su uso en el tratamiento de resistencia a la insulina y/o una enfermedad relacionada con la resistencia a la insulina en un individuo, donde dicho agente se selecciona del grupo que consiste en: a) un polipéptido SorCS1 soluble aislado seleccionado del grupo que consiste en i) una secuencia
