SIRPA and neoplasm: Lactate has long been known as a negative regulator of antitumor immunity.31,32 For example, lactate can induce TAMs to differentiate into an M2-like phenotype by activating HIF-1α, thus promoting tumor development.31 Here, we found that lactate could stimulate the translocation of Ap-2α from the cytoplasm to the nucleus, thus potentiating the Elk-1/Sirpα axis-mediated “don’t eat me” signal.