Plantar Warts

Plantar warts are caused by a variety of Human Papillomaviruses, but the primary one is HPV 1.  The human papillomavirus is a finicky organism, only able to survive and thrive in very specific ecosystems.  It is an insight into the biology of skin that there can be such a difference between the skin of, say, the face and the genitalia, so that the flat warts of HPV 3 are not transmitted to the genitalia, and the genital warts of HPV 16 don't generally pass to the face (although SCCs of the fingers are often associated with HPV 16 having been transmitted from the infected genitalia).  Long story short:  the HPV subtypes are often, but not always, site-specific.  

Why is this?  Obviously, the Hedgehog gene which is the grand conductor of cell differentiation has to play a role, but whether the vulnerability is related to the differentiation of keratin at the different sites or whether it is related to actual histone stimulation of virus activation, I dunno.  It is something to ponder, for sure.

For a bonus point, name the most common of the oncogenic HPVs.

As an additional bonus point, name the recent (relatively recent) book about the cell line that came from a woman from Baltimore whose cervical cancer became "immortal".  One point.