- They show adaptation to definite sites on thebody ,- At least 40 types including HPV6 , 11 , 16 and18 can infect the anogenital tract and othermucosal areas ( sexually transmitted ).- HPV1 and 4 tend to cause plantar warts.- HPV2 , 3 and 10 to cause warts on the kneesand fingers.- Direct and indirect transmission .- DELETE 29.