A method for enhancing the sternness of pluripotent cells which comprises a step wherein the cells are exposed to transient expression or addition of microRNA-203 or an analogue thereof during 3-5 days, and maintaining them in culture in a medium for pluripotent cells during 15 to 30 days, wherein the microRNA-203 analogue is an RNA mimic characterized by: a. being an RNA-modified molecule wherein at least one of the nucleotides is replaced by a chemically modified nucleotide, wherein the chemical modification is selected from the group of: i. replacing one or more phosphate bonds by phosphorothyoate bonds, ii. one or more modifications at the 2' position of the sugar moiety selected from 2'-O-methyl or 2'-O-methoxyethyl modifications; and/or iii. one or more modifications in the ribose moiety selectd from the group of: those that give rise to a link connecting the oxygen at 2' with the carbon at 4', thus blocking the ribose in the conformation 3'-endo (LNAs: locked nucleic acids) or 2'-O, 4'-C ethylene bridged nucleic acids; the replacement of the sugar backbone by an amide-containing backbone such as an aminoethylglycine backbone, as in peptide nucleic acids (PNAs); and use of PMOs (nucleic acids where the ribose moiety is replaced by a morpholine group) b. being a double stranded molecule with a duplex region of between 16 and 31 nucleotides in length and which contains a fragment which is at least 50% identical in their sequence to the sequence of nitrogenous bases of the RNA molecule represented by SEQ ID NO:1, and c. optionally, additionally comprising at at least one end of at least one of the strands a conjugate moiety comprising one or more units of cholesterol, cholestanol, stigmastrol, cholanic acid and ergosterol and, also optionally and additionally, a linker moiety that attaches the conjugate moiety to the strand, and d. also optionally and additionally, presenting one or more mismatches among the two strands. a. being an RNA-modified molecule wherein at least one of the nucleotides is replaced by a chemically modified nucleotide, wherein the chemical modification is selected from the group of: i. replacing one or more phosphate bonds by phosphorothyoate bonds, ii. one or more modifications at the 2' position of the sugar moiety selected from 2'-O-methyl or 2'-O-methoxyethyl modifications; and/or iii. one or more modifications in the ribose moiety selectd from the group of: those that give rise to a link connecting the oxygen at 2' with the carbon at 4', thus blocking the ribose in the conformation 3'-endo (LNAs: locked nucleic acids) or 2'-O, 4'-C ethylene bridged nucleic acids; the replacement of the sugar backbone by an amide-containing backbone such as an aminoethylglycine backbone, as in peptide nucleic acids (PNAs); and use of PMOs (nucleic acids where the ribose moiety is replaced by a morpholine group) i. replacing one or more phosphate bonds by phosphorothyoate bonds, ii. one or more modifications at the 2' position of the sugar moiety selected from 2'-O-methyl or 2'-O-methoxyethyl modifications; and/or iii. one or more modifications in the ribose moiety selectd from the group of: those that give rise to a link connecting the oxygen at 2' with the carbon at 4', thus blocking the ribose in the conformation 3'-endo (LNAs: locked nucleic acids) or 2'-O, 4'-C ethylene bridged nucleic acids; the replacement of the sugar backbone by an amide-containing backbone such as an aminoethylglycine backbone, as in peptide nucleic acids (PNAs); and use of PMOs (nucleic acids where the ribose moiety is replaced by a morpholine group) b. being a double stranded molecule with a duplex region of between 16 and 31 nucleotides in length and which contains a fragment which is at least 50% identical in their sequence to the sequence of nitrogenous bases of the RNA molecule represented by SEQ ID NO:1, and c. optionally, additionally comprising at at least one end of at least one of the strands a conjugate moiety comprising one or more units of cholesterol, cholestanol, stigmastrol, cholanic acid and ergosterol and, also optionally and additionally, a linker moiety that attaches the conjugate moiety to the strand, and d. also optionally and additionally, presenting one or more mismatches among the two strands.