For example, Wang and co-workers coated ferritin (Fn) with CaP to enclose Fn within a “temporary protective shell” by biomineralization technology to increase the enrichment of Fn in the target region, and the TME-responsive dissolution of CaP shell can not only neutralize tumor acidity but also induce intratumor immune regulation and tumor calcification (Fig. 4d–f) [70]. Here, FN1 is linked to neoplasm.