- See Mommy?

- Hi, baby.

- [Lorie] David Fajgenbaum savors each day

like a man living on borrowed time.

Seven years ago he tooka totally different view

as he lay on his death bed.

- I mourned that I wasn't gonna be able

to get married and have a family.

I'd experience those special moments.

- [Lorie] In his book, "Chasing My Cure,"

David recounts how afterdoctors threw in the towel,

he discovered his treatment.

- What are we praying for?

What are we hoping for?

And then we need to ask ourselves,

what can we do to turn that into reality?

- [Lorie] In 2003, David toreup the gridiron at Georgetown,

nicknamed 'The Beast,' thenhe tackled medical school,

where in his third yeah,the doctor in training

suddenly became the patient.

- They did blood work and told me,

"David, your liver, yourkidneys, and your bone marrow

"are shutting down.

"We don't know why.

"We need to hospitalize you right away."

It was terrifying.

- After three months of rapid decline,

doctors diagnosed Davidwith Castleman disease.

Castleman disease is likea cross between cancer

and an autoimmune disorder.

About 5,000 people in theU.S. are diagnosed with it.

Symptoms include sudden, intense fatigue,

fluid retention, and fever.

There was no treatment.

- My family was encouragedto say their goodbyes,

and a priest came in toadminister my last rights to me.

I was so sick.

- [Lorie] A last-ditchchemotherapy drug revived David,

but only briefly.

He would face the brushof death four more times.

- I hoped and I prayed that Iwould find the right doctor,

and they would find theright treatment for me.

- [Lorie] David soon realized

he would need to become that doctor.

- I learned that there wereno more drugs in development.

That there were really no more leads even.

And I said, "I'm gonnadedicate the rest of my life,

"however long that may be, totrying to develop treatments

"and a cure for this disease."

- [Lorie] After testing hisown blood and lymph nodes

for a year, he finallyfound a breakthrough.

- So, the immune systemis really complex with

a number of communication lines,

one of which is called the mTOR pathway,

and I found that thatparticular communication line

was turned into overdrive in my samples.

- [Lorie] While searchingthrough existing medications

targeting that pathway,David hit the jackpot.

- But I thought, "Just maybethis drug for one disease

"could actually help mewith my Castleman disease."

I started on this drug sirolimusfive and a half years ago,

and now it's been five and a half years

that I've been feelinggreat and in remission.

- [Lorie] During that time, hemarried and became a father,

realizing he could relapse any time.

- It's hard to predict howlong these drugs will work for,

and if this diseasewill kind of outmaneuver

the drug that I'm on.

- It's very cliche, butwhen you love someone,

you love someone and youdon't pick how you feel

about people, and I just knew

that I wanted to bewith him no matter what.

- [Lorie] Since David's breakthrough,

about half of a handful ofother Castleman's patients

experienced similar success,

and research continues withDavid leading the charge.

Lorie Johnson, CBN News.