Di Luca was out for 3 but some want more

Well CONI want him out for 2 years, apparently.

Di Luca finished fourth in the 17th stage last year, a climb up the Monte Zoncolan, and was tested directly after the stage. A surprise doping test later that evening showed hormone levels below normal, or equivalent to those of a child, but did not show any banned substances. CONI speculated that he received injections between the end of the stage and the tests, which altered his hormone level. Di Luca, who signed a one-year contract with Team LPR for this season, served a three-month suspension over the winter for his involvement in the "Oil for Drugs" scandal. He has indicated that he will appeal any conviction to the Court of Appeal for Sports (CAS) in Lausanne.

What CONI is saying is that Di Luca's hormone levels were way too low to be believed. They are speculating that he took "something" to mask what were really elevated levels. Presumably these were elevated levels of testosterone, cortisol and Human Growth hormone, or perhaps anything performance-enhancing really. (If I find the list I'll let you know.) Hormones basically control (directly or not) everything from recovery rate to red blood cell production, so to manipulate these values is a big performance advantage. There's no such advantage in having "child-like" values, indeed it would lessen your riding ability, not increase it. So either Di Luca was "sick" or "tired" which suppressed his hormones excessively to these low numbers or he was playing a dangerous game with masking agents.

Of course the testing may be in error. It's a good fall-back but it may be true. However there is one other alternative - if you spend enough time on artificial levels of these hormones your body will shut down most of its own production and become reliant on the supplementary levels. If you reduce this artificial level of input suddenly you fall back to what the body is producing naturally - which would be a suppressed, "child-like" level. After a few days you recover to normal levels as your body senses the lack of hormone. This is also a dangerous game as low levels of various hormones will have undesirable side-effects like passing out, getting the shakes and so on; it can certainly kill you in extremis. It certainly wouldn't enhance your riding.

I personally don't know how Di Luca could ride at his level with "child-like" levels of key hormones. Even just one day of that would knock you back severely. The truth remains "out there" somewhere.