There are multiple definitions:

1. surge inhibiting factor(English)

   • GnSIF

2. singly-innervated [twitch muscle] fiber(English)

   • one category of motoneurons supplying extraocular muscle fibers of vertebrates
   • MIF
   • Neurons, Histochemistry
   • https://doi.org….1002/cne.20715

3. soyabean isoflavone(English)

   • the major class of phytoestrogen that combines with estrogen receptor in advance
   • KiSS-1
   • Estrogen
   • https://doi.org…dis.2020.07.008

4. simulated intestinal fluid(English)

   • used to examine lipolysis of a prodrug in the intestinal tract
   • BUP, SI, TG
   • Pharmacology / pharmaceutics, Metabolism
   • https://doi.org…har.2022.879660

5. small intensely fluorescent [cell](English)

   • ACN, CA, CM, DRA, EF, GP, ICNS, NCC, RSPV, RSVC, SAN, TH
   • Cardiology, Nervous activity - (para)sympathetic
   • https://doi.org…390/jcdd8110149