An agent for use in modulating an activity of an antigen-presenting cell in a subject, wherein the activity is selected from stimulating an antigen-presenting cell to develop an alternatively activated phenotype or preventing or inhibiting the activation of the antigen-presenting cell by an inflammatory stimulus, wherein the agent is selected from: (i) an isolated or purified proteinaceous molecule, which comprises or consists of an amino acid sequence represented by formula I: X 1 X 2 X 3 X 4 DX 5 LX 6 X 7 KX 8 X 9 X 10 X 11 X 12 X 13 X 14 X 15 X 16 X 17 X 18 LX 19 X 20 RX 21 X 22 wherein: X 1 is selected from Y and F; X 2 is selected from L and F; X 3 is selected from E, A, K and R; X 4 is selected from Q, K and E; X 5 is selected from G, N and D; X 6 is selected from G and D; X 7 is selected from E, D and K; X 8 is selected from L, I and M; X 9 is selected from A, S, T and L; X 10 is selected from E, D and A; X 11 is selected from V and I; X 12 is selected from I, L, V and A; X 13 is selected from K, Q, N, S, T, L and V; X 14 is selected from I and V; X 15 is selected from Y, F and L; X 16 is selected from A, S, L and V; X 17 is selected from E, K, Q and N; X 18 is selected from R and P; X 19 is selected from T, P, N and E; X 20 is selected from K, R and D; X 21 is selected from M, I and L; and X 22 is selected from E and D, (ii) an isolated or purified proteinaceous molecule, which comprises or consists of an amino acid sequence represented by formula V: LGJ 1 KJ 2 J 3 J 4 VJ 5 J 6 J 7 J 8 J 9 J 10 RLJ 11 J 12 RJ 13 J 14 wherein: J 1 is selected from E and D; J 2 is selected from L and I; J 3 is selected from A, S and T; J 4 is selected from E, D and A; J 5 is selected from I, L and V; J 6 is selected from K, Q, S, T, L and V; J 7 is selected from I and V; J 8 is selected from Y, F and L; J 9 is selected from A, S, L and V; J 10 is selected from E, K, Q and N; J 11 is selected from T, P and N; J 12 is selected from K, R and D; J 13 is selected from M and L; and J 14 is selected from E and D, (iii) an isolated nucleic acid molecule that comprises or consists of a nucleotide sequence encoding the amino acid sequence of a proteinaceous molecule as defined in (i) or (ii), or (iv) a construct comprising a nucleic acid molecule according to (iii) operably connected to a regulatory sequence. (i) an isolated or purified proteinaceous molecule, which comprises or consists of an amino acid sequence represented by formula I: X 1 X 2 X 3 X 4 DX 5 LX 6 X 7 KX 8 X 9 X 10 X 11 X 12 X 13 X 14 X 15 X 16 X 17 X 18 LX 19 X 20 RX 21 X 22 wherein: X 1 is selected from Y and F; X 2 is selected from L and F; X 3 is selected from E, A, K and R; X 4 is selected from Q, K and E; X 5 is selected from G, N and D; X 6 is selected from G and D; X 7 is selected from E, D and K; X 8 is selected from L, I and M; X 9 is selected from A, S, T and L; X 10 is selected from E, D and A; X 11 is selected from V and I; X 12 is selected from I, L, V and A; X 13 is selected from K, Q, N, S, T, L and V; X 14 is selected from I and V; X 15 is selected from Y, F and L; X 16 is selected from A, S, L and V; X 17 is selected from E, K, Q and N; X 18 is selected from R and P; X 19 is selected from T, P, N and E; X 20 is selected from K, R and D; X 21 is selected from M, I and L; and X 22 is selected from E and D, X 1 is selected from Y and F; X 2 is selected from L and F; X 3 is selected from E, A, K and R; X 4 is selected from Q, K and E; X 5 is selected from G, N and D; X 6 is selected from G and D; X 7 is selected from E, D and K; X 8 is selected from L, I and M; X 9 is selected from A, S, T and L; X 10 is selected from E, D and A; X 11 is selected from V and I; X 12 is selected from I, L, V and A; X 13 is selected from K, Q, N, S, T, L and V; X 14 is selected from I and V; X 15 is selected from Y, F and L; X 16 is selected from A, S, L and V; X 17 is selected from E, K, Q and N; X 18 is selected from R and P; X 19 is selected from T, P, N and E; X 20 is selected from K, R and D; X 21 is selected from M, I and L; and X 22 is selected from E and D, (ii) an isolated or purified proteinaceous molecule, which comprises or consists of an amino acid sequence represented by formula V: LGJ 1 KJ 2 J 3 J 4 VJ 5 J 6 J 7 J 8 J 9 J 10 RLJ 11 J 12 RJ 13 J 14 wherein: J 1 is selected from E and D; J 2 is selected from L and I; J 3 is selected from A, S and T; J 4 is selected from E, D and A; J 5 is selected from I, L and V; J 6 is selected from K, Q, S, T, L and V; J 7 is selected from I and V; J 8 is selected from Y, F and L; J 9 is selected from A, S, L and V; J 10 is selected from E, K, Q and N; J 11 is selected from T, P and N; J 12 is selected from K, R and D; J 13 is selected from M and L; and J 14 is selected from E and D, J 1 is selected from E and D; J 2 is selected from L and I; J 3 is selected from A, S and T; J 4 is selected from E, D and A; J 5 is selected from I, L and V; J 6 is selected from K, Q, S, T, L and V; J 7 is selected from I and V; J 8 is selected from Y, F and L; J 9 is selected from A, S, L and V; J 10 is selected from E, K, Q and N; J 11 is selected from T, P and N; J 12 is selected from K, R and D; J 13 is selected from M and L; and J 14 is selected from E and D, (iii) an isolated nucleic acid molecule that comprises or consists of a nucleotide sequence encoding the amino acid sequence of a proteinaceous molecule as defined in (i) or (ii), or (iv) a construct comprising a nucleic acid molecule according to (iii) operably connected to a regulatory sequence.