MMP3 and nasopharyngeal carcinoma: Subsequently, six subtypes of NP cells, namely, metabolic homeostatic NP cells [Met NPC, highly expressing MXRA5 and DKK3 (Li et al., 2017; Poveda et al., 2017)], adhesive NP cells [Adh NPC, highly expressing VCAM1 (Rafat et al., 2012)], inflammatory response NP cells (IR NPC, highly expressing MMP3 and ADAMTS5), endoplasmic reticulum stress NP cells [ERS NPC, highly expressing TXNIP and HSPA1B (Ding et al., 2020)], fibrocartilagenous NP cells [Fc NPC, highly expressing FGF1 (Fernández et al., 2010)], and CD70+ and CD82+ progenitor NP cells (Pro NPC), were identified.