Of the cytokines analysed, nine (CD30L, CCL11, CCL24, IGFBP5, IL-4, IL-13, MIP-3ß, CXCL4 and TPO) were significantly more abundant in 4T1 primary tumours than in 67NR primary tumours (Fig. 4aiii, iv and Table 1). Here, TPO is linked to neoplasm.