CXCL12 and infection: The mRNA expression levels of the chemokines Ccl3 and Cxcl12 and the levels of Igf1 in thymocytes were clearly upregulated due to protein malnutrition or infection conditions separately (Fig. 5C–E) (Ccl3 p < 0.01; Cxcl12 p < 0.05 and Igf1 p < 0.001).