1. Decreased expression of the c-kit receptor is associated with increased apoptosis in subfertile human testes 
Huai L Feng, Ph.D., Jay I Sandlow, M.D., Amy E.T Sparks, Ph.D., Alexander Sandra, Ph.D., Lei J Zheng, B.S. 
Fertility and Sterility 
Volume 71, Issue 1, Pages (January 1999)
DOI: /S (98)

2. FIGURE 1
Western blot analysis of the c-kit receptor protein. Western blot showing the expression of the c-kit receptor protein of 150 kd in normal (lane NL) and maturationally arrested (lane MA) testicular tissues. No band was noted in Sertoli cell–only tissue (lane S).
Fertility and Sterility  , 85-89DOI: ( /S (98) )

3. FIGURE 2
Western blot analysis of the SCF protein. Western blot showing the expression of the SCF protein of 45 kd (arrow) in normal (lane NL), maturationally arrested (lane MA), and Sertoli cell–only (lane S) testicular tissues.
Fertility and Sterility  , 85-89DOI: ( /S (98) )

4. FIGURE 3
Apoptosis bodies in testicular biopsy specimens. (A), Normal testicular tissue showing a low incidence of apoptosis. (B), Spermatogonia and spermatocytes showing a significantly increased incidence of apoptosis (arrows). (C), Leydig cells (arrow) in Sertoli cell–only pattern showing increased apoptosis. Bar = 10 μm.
Fertility and Sterility  , 85-89DOI: ( /S (98) )