POSTN and melanoma: TAMs release CXCL5 via stimulation of periostin [26], and the tumor stroma of melanoma possesses prominent periostin [27, 28] and TAMs [8, 12], so the increased serum levels of sCD163 and CXCL5 in a patient who develops adverse nivolumab-induced, immune-related events are presumably related to periostin-stimulated TAM activation.